From feaef10505144cb51b889bce54d3f9c158873273 Mon Sep 17 00:00:00 2001
From: Felix Chan You Yuan <e0959017@u.nus.edu>
Date: Fri, 29 Mar 2024 02:44:42 +0800
Subject: [PATCH] Add Budget class for Buyer class

Addition of the Budget class is necessary to represent the budget
attribute for Buyer objects.

Implemented the Budget class to encapsulate the budget information
for buyers, allowing for better organization and management of
budget-related data.

Using a separate class for budget ensures separation of concerns and
follows the single responsibility principle, improving code
readability and maintainability.

This commit also includes necessary adjustments to integrate the
Budget class with the Buyer class.
---
 .../logic/commands/AddBuyerCommand.java       |  3 +
 .../logic/parser/AddBuyerCommandParser.java   | 13 ++--
 .../seedu/address/logic/parser/CliSyntax.java |  1 +
 .../address/logic/parser/ParserUtil.java      | 16 +++++
 .../seedu/address/model/person/Budget.java    | 58 ++++++++++++++++
 .../seedu/address/model/person/Buyer.java     | 48 +++++++++++++-
 .../address/model/util/SampleDataUtil.java    |  7 +-
 .../address/storage/JsonAdaptedBuyer.java     | 17 ++++-
 .../java/seedu/address/ui/PersonCard.java     |  7 ++
 src/main/resources/view/PersonListCard.fxml   |  1 +
 .../duplicatePersonAddressBook.json           |  1 +
 .../typicalPersonsAddressBook.json            |  5 +-
 .../logic/commands/AddBuyerCommandTest.java   |  6 +-
 .../logic/commands/CommandTestUtil.java       |  8 +++
 .../logic/parser/AddressBookParserTest.java   |  3 +-
 .../seedu/address/model/person/BuyerTest.java | 66 ++++++++++---------
 .../address/storage/JsonAdaptedBuyerTest.java | 42 ++++++++++--
 .../storage/JsonAddressBookStorageTest.java   |  6 +-
 .../seedu/address/testutil/BuyerBuilder.java  | 15 ++++-
 .../seedu/address/testutil/PersonUtil.java    | 22 ++++++-
 .../address/testutil/TypicalPersons.java      | 31 +++++++--
 21 files changed, 309 insertions(+), 67 deletions(-)
 create mode 100644 src/main/java/seedu/address/model/person/Budget.java

diff --git a/src/main/java/seedu/address/logic/commands/AddBuyerCommand.java b/src/main/java/seedu/address/logic/commands/AddBuyerCommand.java
index 63d51526c19..d3ce44e92c3 100644
--- a/src/main/java/seedu/address/logic/commands/AddBuyerCommand.java
+++ b/src/main/java/seedu/address/logic/commands/AddBuyerCommand.java
@@ -1,6 +1,7 @@
 package seedu.address.logic.commands;
 
 import static java.util.Objects.requireNonNull;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_BUDGET;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_HOUSING_TYPE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
@@ -26,12 +27,14 @@ public class AddBuyerCommand extends Command {
             + PREFIX_PHONE + "PHONE "
             + PREFIX_EMAIL + "EMAIL "
             + PREFIX_HOUSING_TYPE + "HOUSING_TYPE "
+            + PREFIX_BUDGET + "BUDGET "
             + "[" + PREFIX_TAG + "TAG]...\n"
             + "Example: " + COMMAND_WORD + " "
             + PREFIX_NAME + "John Doe "
             + PREFIX_PHONE + "98765432 "
             + PREFIX_EMAIL + "johnd@example.com "
             + PREFIX_HOUSING_TYPE + "HDB "
+            + PREFIX_BUDGET + "99999900 "
             + PREFIX_TAG + "friends "
             + PREFIX_TAG + "owesMoney";
 
diff --git a/src/main/java/seedu/address/logic/parser/AddBuyerCommandParser.java b/src/main/java/seedu/address/logic/parser/AddBuyerCommandParser.java
index 55f6f96577d..f339c678c70 100644
--- a/src/main/java/seedu/address/logic/parser/AddBuyerCommandParser.java
+++ b/src/main/java/seedu/address/logic/parser/AddBuyerCommandParser.java
@@ -1,6 +1,7 @@
 package seedu.address.logic.parser;
 
 import static seedu.address.logic.Messages.MESSAGE_INVALID_COMMAND_FORMAT;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_BUDGET;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_HOUSING_TYPE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_NAME;
@@ -12,6 +13,7 @@
 
 import seedu.address.logic.commands.AddBuyerCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -31,21 +33,24 @@ public class AddBuyerCommandParser implements Parser<AddBuyerCommand> {
     public AddBuyerCommand parse(String args) throws ParseException {
         ArgumentMultimap argMultimap =
                 ArgumentTokenizer.tokenize(args, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_HOUSING_TYPE,
-                        PREFIX_TAG);
+                        PREFIX_BUDGET, PREFIX_TAG);
 
-        if (!arePrefixesPresent(argMultimap, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_HOUSING_TYPE)
+        if (!arePrefixesPresent(argMultimap, PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_HOUSING_TYPE,
+                PREFIX_BUDGET)
                 || !argMultimap.getPreamble().isEmpty()) {
             throw new ParseException(String.format(MESSAGE_INVALID_COMMAND_FORMAT, AddBuyerCommand.MESSAGE_USAGE));
         }
 
-        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_HOUSING_TYPE);
+        argMultimap.verifyNoDuplicatePrefixesFor(PREFIX_NAME, PREFIX_PHONE, PREFIX_EMAIL, PREFIX_HOUSING_TYPE,
+                PREFIX_BUDGET);
         Name name = ParserUtil.parseName(argMultimap.getValue(PREFIX_NAME).get());
         Phone phone = ParserUtil.parsePhone(argMultimap.getValue(PREFIX_PHONE).get());
         Email email = ParserUtil.parseEmail(argMultimap.getValue(PREFIX_EMAIL).get());
         String housingType = ParserUtil.parseHousing(argMultimap.getValue(PREFIX_HOUSING_TYPE).get());
         Set<Tag> tagList = ParserUtil.parseTags(argMultimap.getAllValues(PREFIX_TAG));
+        Budget budget = ParserUtil.parseBudget(argMultimap.getValue(PREFIX_BUDGET).get());
 
-        Buyer buyer = new Buyer(name, phone, email, housingType, tagList);
+        Buyer buyer = new Buyer(name, phone, email, housingType, budget, tagList);
         return new AddBuyerCommand(buyer);
     }
 
diff --git a/src/main/java/seedu/address/logic/parser/CliSyntax.java b/src/main/java/seedu/address/logic/parser/CliSyntax.java
index 8109c14f565..8ac0fb5a365 100644
--- a/src/main/java/seedu/address/logic/parser/CliSyntax.java
+++ b/src/main/java/seedu/address/logic/parser/CliSyntax.java
@@ -16,4 +16,5 @@ public class CliSyntax {
     public static final Prefix PREFIX_UNITNUMBER = new Prefix("unitNo/");
     public static final Prefix PREFIX_BLOCK = new Prefix("blk/");
     public static final Prefix PREFIX_POSTALCODE = new Prefix("postal/");
+    public static final Prefix PREFIX_BUDGET = new Prefix("b/");
 }
diff --git a/src/main/java/seedu/address/logic/parser/ParserUtil.java b/src/main/java/seedu/address/logic/parser/ParserUtil.java
index d9ecf15ec7a..5c08e3f6344 100644
--- a/src/main/java/seedu/address/logic/parser/ParserUtil.java
+++ b/src/main/java/seedu/address/logic/parser/ParserUtil.java
@@ -16,6 +16,7 @@
 import seedu.address.model.house.Street;
 import seedu.address.model.house.UnitNumber;
 import seedu.address.model.person.Address;
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
 import seedu.address.model.person.Phone;
@@ -217,4 +218,19 @@ public static PostalCode parsePostalCode(String postalCode) throws ParseExceptio
         }
         return new PostalCode(trimmedPostalCode);
     }
+
+    /**
+     * Parses a {@code String budget} into an {@code Budget}
+     * Loading and trailing whitespaces will be trimmed
+     *
+     * @throws ParseException if the given {@code budget} is invalid
+     */
+    public static Budget parseBudget(String budget) throws ParseException {
+        requireNonNull(budget);
+        String trimmedBudget = budget.trim();
+        if (!Budget.isValidBudget(trimmedBudget)) {
+            throw new ParseException(Budget.MESSAGE_CONSTRAINTS);
+        }
+        return new Budget(trimmedBudget);
+    }
 }
diff --git a/src/main/java/seedu/address/model/person/Budget.java b/src/main/java/seedu/address/model/person/Budget.java
new file mode 100644
index 00000000000..e6fee05d058
--- /dev/null
+++ b/src/main/java/seedu/address/model/person/Budget.java
@@ -0,0 +1,58 @@
+package seedu.address.model.person;
+
+import static java.util.Objects.requireNonNull;
+import static seedu.address.commons.util.AppUtil.checkArgument;
+
+/**
+ * Represents a Buyer's budget in the address book.
+ * Guarantees: immutable; is valid as declared in {@link #isValidBudget(String)}
+ */
+public class Budget {
+
+    public static final String MESSAGE_CONSTRAINTS = "Budget should be a positive number.";
+    public static final String VALIDATION_REGEX = "\\d+(\\.\\d+)?";
+    public final String value;
+
+    /**
+     * Constructs a {@code Budget}.
+     *
+     * @param budget A valid budget amount.
+     */
+    public Budget(String budget) {
+        requireNonNull(budget);
+        checkArgument(isValidBudget(budget), MESSAGE_CONSTRAINTS);
+        value = budget;
+    }
+
+    /**
+     * Returns true if a given string is a valid budget amount.
+     */
+    public static boolean isValidBudget(String test) {
+        return test.matches(VALIDATION_REGEX) && Double.parseDouble(test) >= 0;
+    }
+
+    @Override
+    public String toString() {
+        return value;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (other == this) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof Budget)) {
+            return false;
+        }
+
+        Budget otherBudget = (Budget) other;
+        return value.equals(otherBudget.value);
+    }
+
+    @Override
+    public int hashCode() {
+        return value.hashCode();
+    }
+}
diff --git a/src/main/java/seedu/address/model/person/Buyer.java b/src/main/java/seedu/address/model/person/Buyer.java
index ab2ae18e5ba..80fe66ed3ee 100644
--- a/src/main/java/seedu/address/model/person/Buyer.java
+++ b/src/main/java/seedu/address/model/person/Buyer.java
@@ -1,7 +1,9 @@
 package seedu.address.model.person;
 
+import java.util.Objects;
 import java.util.Set;
 
+import seedu.address.commons.util.ToStringBuilder;
 import seedu.address.model.tag.Tag;
 
 /**
@@ -9,6 +11,8 @@
  */
 public class Buyer extends Person {
 
+    private final Budget budget;
+
     /**
      * Constructs a new Buyer instance without specifying a house. Default constructor.
      *
@@ -17,8 +21,50 @@ public class Buyer extends Person {
      * @param email       The email address of the buyer.
      * @param housingType The type of housing the buyer wants.
      * @param tags        The tags associated with the buyer.
+     * @param budget      The budget of the buyer.
      */
-    public Buyer(Name name, Phone phone, Email email, String housingType, Set<Tag> tags) {
+    public Buyer(Name name, Phone phone, Email email, String housingType, Budget budget, Set<Tag> tags) {
         super(name, phone, email, housingType, tags);
+        this.budget = budget;
+    }
+
+    public Budget getBudget() {
+        return budget;
+    }
+
+    @Override
+    public boolean equals(Object other) {
+        if (this == other) {
+            return true;
+        }
+
+        // instanceof handles nulls
+        if (!(other instanceof Buyer)) {
+            return false;
+        }
+
+        if (!super.equals(other)) {
+            return false;
+        }
+
+        Buyer buyer = (Buyer) other;
+        return Objects.equals(budget, buyer.budget);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(super.hashCode(), budget);
+    }
+
+    @Override
+    public String toString() {
+        return new ToStringBuilder(this)
+                .add("name", getName())
+                .add("phone", getPhone())
+                .add("email", getEmail())
+                .add("housingType", getHousingType())
+                .add("budget", budget)
+                .add("tags", getTags())
+                .toString();
     }
 }
diff --git a/src/main/java/seedu/address/model/util/SampleDataUtil.java b/src/main/java/seedu/address/model/util/SampleDataUtil.java
index 355dee4918e..0078516002b 100644
--- a/src/main/java/seedu/address/model/util/SampleDataUtil.java
+++ b/src/main/java/seedu/address/model/util/SampleDataUtil.java
@@ -14,6 +14,7 @@
 import seedu.address.model.house.PostalCode;
 import seedu.address.model.house.Street;
 import seedu.address.model.house.UnitNumber;
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -28,13 +29,13 @@ public class SampleDataUtil {
     public static Buyer[] getSampleBuyers() {
         return new Buyer[] {
             new Buyer(new Name("Alex Yeoh"), new Phone("87438807"),
-                        new Email("alexyeoh@example.com"), "HDB",
+                        new Email("alexyeoh@example.com"), "HDB", new Budget("100000"),
                         getTagSet("friends")),
             new Buyer(new Name("Bernice Yu"), new Phone("99272758"),
-                        new Email("berniceyu@example.com"), "Condominium",
+                        new Email("berniceyu@example.com"), "Condominium", new Budget("200000"),
                         getTagSet("colleagues", "friends")),
             new Buyer(new Name("Charlotte Oliveiro"), new Phone("93210283"),
-                        new Email("charlotte@example.com"), "HDB",
+                        new Email("charlotte@example.com"), "HDB", new Budget("300000"),
                         getTagSet("neighbours")),
         };
     }
diff --git a/src/main/java/seedu/address/storage/JsonAdaptedBuyer.java b/src/main/java/seedu/address/storage/JsonAdaptedBuyer.java
index d3a85da6a4d..5af746d5404 100644
--- a/src/main/java/seedu/address/storage/JsonAdaptedBuyer.java
+++ b/src/main/java/seedu/address/storage/JsonAdaptedBuyer.java
@@ -7,6 +7,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import seedu.address.commons.exceptions.IllegalValueException;
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Person;
 
@@ -15,6 +16,8 @@
  */
 public class JsonAdaptedBuyer extends JsonAdaptedPerson {
 
+    private final String budget;
+
     /**
      * Constructs a {@code JsonAdaptedBuyer}, extends from JsonAdaptedPerson
      */
@@ -23,8 +26,10 @@ public JsonAdaptedBuyer(@JsonProperty("name") String name,
                              @JsonProperty("phone") String phone,
                              @JsonProperty("email") String email,
                              @JsonProperty("housingType") String housingType,
+                             @JsonProperty("budget") String budget,
                              @JsonProperty("tags") List<JsonAdaptedTag> tags) {
         super(name, phone, email, housingType, tags);
+        this.budget = budget;
     }
 
     /**
@@ -32,6 +37,7 @@ public JsonAdaptedBuyer(@JsonProperty("name") String name,
      */
     public JsonAdaptedBuyer(Buyer source) {
         super(source);
+        budget = source.getBudget().value;
     }
 
     /**
@@ -39,8 +45,17 @@ public JsonAdaptedBuyer(Buyer source) {
      */
     @Override
     public Buyer toModelType() throws IllegalValueException {
+
+        if (budget == null) {
+            throw new IllegalValueException(String.format(MISSING_FIELD_MESSAGE_FORMAT, Budget.class.getSimpleName()));
+        }
+        if (!Budget.isValidBudget(budget)) {
+            throw new IllegalValueException(Budget.MESSAGE_CONSTRAINTS);
+        }
+        final Budget modelBudget = new Budget(budget);
+
         Person person = super.toModelType();
         return new Buyer(person.getName(), person.getPhone(), person.getEmail(),
-                person.getHousingType(), new HashSet<>(person.getTags()));
+                person.getHousingType(), modelBudget, new HashSet<>(person.getTags()));
     }
 }
diff --git a/src/main/java/seedu/address/ui/PersonCard.java b/src/main/java/seedu/address/ui/PersonCard.java
index d677a5096d6..3d26bd3eb8a 100644
--- a/src/main/java/seedu/address/ui/PersonCard.java
+++ b/src/main/java/seedu/address/ui/PersonCard.java
@@ -11,6 +11,7 @@
 import seedu.address.model.house.Block;
 import seedu.address.model.house.Level;
 import seedu.address.model.house.NonLanded;
+import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Person;
 import seedu.address.model.person.Seller;
 
@@ -34,6 +35,8 @@ public class PersonCard extends UiPart<Region> {
     @FXML
     private Label housingType;
     @FXML
+    private Label budget;
+    @FXML
     private Label email;
     @FXML
     private Label postalCode;
@@ -59,6 +62,8 @@ public PersonCard(Person person, int displayedIndex) {
 
         // Check if person is a Seller and display houses (For now, we assume only have seller have house)
         if (person instanceof Seller) {
+            // Show no budget
+            budget.setVisible(false);
             Seller seller = (Seller) person;
             if (seller.getHouses() != null) {
                 seller.getHouses().forEach(house -> {
@@ -92,6 +97,8 @@ public PersonCard(Person person, int displayedIndex) {
         } else {
             // We assumed that buyer does not have a house for now
             housesContainer.setVisible(false);
+            Buyer buyer = (Buyer) person;
+            budget.setText("$" + buyer.getBudget().toString());
         }
     }
 }
diff --git a/src/main/resources/view/PersonListCard.fxml b/src/main/resources/view/PersonListCard.fxml
index acbaf5a62e0..23d255554f2 100644
--- a/src/main/resources/view/PersonListCard.fxml
+++ b/src/main/resources/view/PersonListCard.fxml
@@ -32,6 +32,7 @@
             <Label fx:id="phone" styleClass="cell_small_label" text="\$phone"/>
             <Label fx:id="email" styleClass="cell_small_label" text="\$email"/>
             <Label fx:id="housingType" styleClass="cell_small_label" text="\$housingType"/>
+            <Label fx:id="budget" styleClass="cell_small_label" text="\$budget"/>
         </VBox>
         <!-- New VBox for displaying houses -->
         <VBox fx:id="housesContainer" alignment="TOP_LEFT" GridPane.columnIndex="1">
diff --git a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
index 0945525917d..b5d39085d63 100644
--- a/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/duplicatePersonAddressBook.json
@@ -21,6 +21,7 @@
     "phone" : "94351253",
     "email" : "alice@example.com",
     "housingType" : "HDB",
+    "budget": "22200",
     "tags" : [ "friends" ]
   } ]
 }
diff --git a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
index b58b7c5bd92..cbefe6ac12a 100644
--- a/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
+++ b/src/test/data/JsonSerializableAddressBookTest/typicalPersonsAddressBook.json
@@ -114,9 +114,10 @@
   } ],
   "buyers" : [ {
     "name" : "Ben Ten",
-    "phone" : "22222222",
-    "email" : "bob@example.com",
+    "phone" : "33333333",
+    "email" : "ben@example.com",
     "housingType" : "Condominium",
+    "budget": "123000",
     "tags" : [ "friend", "husband" ]
   } ]
 }
diff --git a/src/test/java/seedu/address/logic/commands/AddBuyerCommandTest.java b/src/test/java/seedu/address/logic/commands/AddBuyerCommandTest.java
index 4ea64f7a2cc..8a1b78a0d43 100644
--- a/src/test/java/seedu/address/logic/commands/AddBuyerCommandTest.java
+++ b/src/test/java/seedu/address/logic/commands/AddBuyerCommandTest.java
@@ -5,7 +5,7 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.testutil.Assert.assertThrows;
-import static seedu.address.testutil.TypicalPersons.ALI;
+import static seedu.address.testutil.TypicalPersons.ALI_BUYER;
 
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -79,8 +79,8 @@ public void equals() {
 
     @Test
     public void toStringMethod() {
-        AddBuyerCommand addBuyerCommand = new AddBuyerCommand(ALI);
-        String expected = AddBuyerCommand.class.getCanonicalName() + "{buyerToAdd=" + ALI + "}";
+        AddBuyerCommand addBuyerCommand = new AddBuyerCommand(ALI_BUYER);
+        String expected = AddBuyerCommand.class.getCanonicalName() + "{buyerToAdd=" + ALI_BUYER + "}";
         assertEquals(expected, addBuyerCommand.toString());
     }
 
diff --git a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
index 6fbb061340b..89e7ea528f9 100644
--- a/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
+++ b/src/test/java/seedu/address/logic/commands/CommandTestUtil.java
@@ -3,6 +3,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_BLOCK;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_BUDGET;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_HOUSING_TYPE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_LEVEL;
@@ -36,10 +37,16 @@ public class CommandTestUtil {
     public static final String VALID_NAME_BEN = "Ben Ten";
     public static final String VALID_PHONE_AMY = "11111111";
     public static final String VALID_PHONE_BOB = "22222222";
+    public static final String VALID_PHONE_BEN = "33333333";
     public static final String VALID_EMAIL_AMY = "amy@example.com";
     public static final String VALID_EMAIL_BOB = "bob@example.com";
+    public static final String VALID_EMAIL_BEN = "ben@example.com";
     public static final String VALID_HOUSING_TYPE_AMY = "HDB";
     public static final String VALID_HOUSING_TYPE_BOB = "Condominium";
+    public static final String VALID_HOUSING_TYPE_BEN = "Condominium";
+    public static final String VALID_BUDGET_AMY = "999000";
+    public static final String VALID_BUDGET_BOB = "1000000";
+    public static final String VALID_BUDGET_BEN = "123000";
     public static final String VALID_TAG_HUSBAND = "husband";
     public static final String VALID_TAG_FRIEND = "friend";
     public static final String VALID_BLOCK_AMY = "99B";
@@ -78,6 +85,7 @@ public class CommandTestUtil {
     public static final String INVALID_PHONE_DESC = " " + PREFIX_PHONE + "911a"; // 'a' not allowed in phones
     public static final String INVALID_EMAIL_DESC = " " + PREFIX_EMAIL + "bob!yahoo"; // missing '@' symbol
     public static final String INVALID_HOUSING_TYPE_DESC = " " + PREFIX_HOUSING_TYPE;
+    public static final String INVALID_BUDGET_DESC = " " + PREFIX_BUDGET; // "" not allowed in budget
     public static final String INVALID_TAG_DESC = " " + PREFIX_TAG + "hubby*"; // '*' not allowed in tags
 
     public static final String PREAMBLE_WHITESPACE = "\t  \r  \n";
diff --git a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
index d7f1bb29d61..04ba5b056f8 100644
--- a/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
+++ b/src/test/java/seedu/address/logic/parser/AddressBookParserTest.java
@@ -23,6 +23,7 @@
 import seedu.address.logic.commands.HelpCommand;
 import seedu.address.logic.commands.ListCommand;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.model.person.Buyer;
 import seedu.address.model.person.NameContainsKeywordsPredicate;
 import seedu.address.model.person.Person;
 import seedu.address.testutil.BuyerBuilder;
@@ -36,7 +37,7 @@ public class AddressBookParserTest {
 
     @Test
     public void parseCommand_addBuyer() throws Exception {
-        Person buyer = new BuyerBuilder().build();
+        Buyer buyer = new BuyerBuilder().build();
         AddBuyerCommand command = (AddBuyerCommand) parser.parseCommand(PersonUtil.getAddBuyerCommand(buyer));
         assertEquals(new AddBuyerCommand(buyer), command);
     }
diff --git a/src/test/java/seedu/address/model/person/BuyerTest.java b/src/test/java/seedu/address/model/person/BuyerTest.java
index 07b7f17fadc..9c9efcf9cd8 100644
--- a/src/test/java/seedu/address/model/person/BuyerTest.java
+++ b/src/test/java/seedu/address/model/person/BuyerTest.java
@@ -10,8 +10,8 @@
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
-import static seedu.address.testutil.TypicalPersons.ALI;
-import static seedu.address.testutil.TypicalPersons.BEN;
+import static seedu.address.testutil.TypicalPersons.ALI_BUYER;
+import static seedu.address.testutil.TypicalPersons.BEN_BUYER;
 import static seedu.address.testutil.TypicalPersons.BOB;
 
 import org.junit.jupiter.api.Test;
@@ -29,76 +29,78 @@ public void asObservableList_modifyList_throwsUnsupportedOperationException() {
     @Test
     public void isSamePerson() {
         // same object -> returns true
-        assertTrue(ALI.isSamePerson(ALI));
+        assertTrue(ALI_BUYER.isSamePerson(ALI_BUYER));
 
         // null -> returns false
-        assertFalse(ALI.isSamePerson(null));
+        assertFalse(ALI_BUYER.isSamePerson(null));
 
         // same name, all other attributes different -> returns true
-        Person editedAli = new BuyerBuilder(ALI).withPhone(VALID_PHONE_BOB).withEmail(VALID_EMAIL_BOB)
+        Person editedAli = new BuyerBuilder(ALI_BUYER).withPhone(VALID_PHONE_BOB).withEmail(VALID_EMAIL_BOB)
                 .withHousingType(VALID_HOUSING_TYPE_BOB).withTags(VALID_TAG_HUSBAND).build();
-        assertTrue(ALI.isSamePerson(editedAli));
+        assertTrue(ALI_BUYER.isSamePerson(editedAli));
 
         // different name, all other attributes same -> returns false
-        editedAli = new BuyerBuilder(ALI).withName(VALID_NAME_BEN).build();
-        assertFalse(ALI.isSamePerson(editedAli));
+        editedAli = new BuyerBuilder(ALI_BUYER).withName(VALID_NAME_BEN).build();
+        assertFalse(ALI_BUYER.isSamePerson(editedAli));
 
         // name differs in case, all other attributes same -> returns false
-        Person editedBen = new BuyerBuilder(BEN).withName(VALID_NAME_BEN.toLowerCase()).build();
-        assertFalse(BEN.isSamePerson(editedBen));
+        Person editedBen = new BuyerBuilder(BEN_BUYER).withName(VALID_NAME_BEN.toLowerCase()).build();
+        assertFalse(BEN_BUYER.isSamePerson(editedBen));
 
         // name has trailing spaces, all other attributes same -> returns false
         String nameWithTrailingSpaces = VALID_NAME_BEN + " ";
-        editedBen = new BuyerBuilder(BEN).withName(nameWithTrailingSpaces).build();
-        assertFalse(BEN.isSamePerson(editedBen));
+        editedBen = new BuyerBuilder(BEN_BUYER).withName(nameWithTrailingSpaces).build();
+        assertFalse(BEN_BUYER.isSamePerson(editedBen));
     }
 
     @Test
     public void equals() {
 
-        Person buyerAliCopy = new BuyerBuilder(ALI).build();
+        Person buyerAliCopy = new BuyerBuilder(ALI_BUYER).build();
 
         // same object -> returns true
-        assertTrue(ALI.equals(buyerAliCopy));
+        assertTrue(ALI_BUYER.equals(buyerAliCopy));
 
         // same object -> returns true
-        assertTrue(ALI.equals(ALI));
+        assertTrue(ALI_BUYER.equals(ALI_BUYER));
 
         // null -> returns false
-        assertFalse(ALI.equals(null));
+        assertFalse(ALI_BUYER.equals(null));
 
         // different type -> returns false
-        assertFalse(ALI.equals(5));
+        assertFalse(ALI_BUYER.equals(5));
 
         // different person -> returns false
-        assertFalse(ALI.equals(BOB));
+        assertFalse(ALI_BUYER.equals(BOB));
 
         // different name -> returns false
-        Person editedAli = new BuyerBuilder(ALI).withName(VALID_NAME_BOB).build();
-        assertFalse(ALI.equals(editedAli));
+        Person editedAli = new BuyerBuilder(ALI_BUYER).withName(VALID_NAME_BOB).build();
+        assertFalse(ALI_BUYER.equals(editedAli));
 
         // different phone -> returns false
-        editedAli = new BuyerBuilder(ALI).withPhone(VALID_PHONE_BOB).build();
-        assertFalse(ALI.equals(editedAli));
+        editedAli = new BuyerBuilder(ALI_BUYER).withPhone(VALID_PHONE_BOB).build();
+        assertFalse(ALI_BUYER.equals(editedAli));
 
         // different email -> returns false
-        editedAli = new BuyerBuilder(ALI).withEmail(VALID_EMAIL_BOB).build();
-        assertFalse(ALI.equals(editedAli));
+        editedAli = new BuyerBuilder(ALI_BUYER).withEmail(VALID_EMAIL_BOB).build();
+        assertFalse(ALI_BUYER.equals(editedAli));
 
         // different housingtype -> returns false
-        editedAli = new BuyerBuilder(ALI).withHousingType(VALID_HOUSING_TYPE_BOB).build();
-        assertFalse(ALI.equals(editedAli));
+        editedAli = new BuyerBuilder(ALI_BUYER).withHousingType(VALID_HOUSING_TYPE_BOB).build();
+        assertFalse(ALI_BUYER.equals(editedAli));
 
         // different tags -> returns false
-        editedAli = new BuyerBuilder(ALI).withTags(VALID_TAG_HUSBAND).build();
-        assertFalse(ALI.equals(editedAli));
+        editedAli = new BuyerBuilder(ALI_BUYER).withTags(VALID_TAG_HUSBAND).build();
+        assertFalse(ALI_BUYER.equals(editedAli));
     }
 
     @Test
     public void toStringMethod() {
-        String expected = Buyer.class.getCanonicalName() + "{name=" + ALI.getName() + ", phone=" + ALI.getPhone()
-                + ", email=" + ALI.getEmail() + ", housingType=" + ALI.getHousingType()
-                + ", tags=" + ALI.getTags() + "}";
-        assertEquals(expected, ALI.toString());
+        String expected = Buyer.class.getCanonicalName() + "{name="
+                + ALI_BUYER.getName() + ", phone=" + ALI_BUYER.getPhone()
+                + ", email=" + ALI_BUYER.getEmail() + ", housingType=" + ALI_BUYER.getHousingType()
+                + ", budget=" + ALI_BUYER.getBudget()
+                + ", tags=" + ALI_BUYER.getTags() + "}";
+        assertEquals(expected, ALI_BUYER.toString());
     }
 }
diff --git a/src/test/java/seedu/address/storage/JsonAdaptedBuyerTest.java b/src/test/java/seedu/address/storage/JsonAdaptedBuyerTest.java
index 30fb9982e9d..8b5c0445ba2 100644
--- a/src/test/java/seedu/address/storage/JsonAdaptedBuyerTest.java
+++ b/src/test/java/seedu/address/storage/JsonAdaptedBuyerTest.java
@@ -12,6 +12,7 @@
 import org.junit.jupiter.api.Test;
 
 import seedu.address.commons.exceptions.IllegalValueException;
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
 import seedu.address.model.person.Phone;
@@ -21,12 +22,14 @@ public class JsonAdaptedBuyerTest {
     private static final String INVALID_PHONE = "+651234";
     private static final String INVALID_EMAIL = "example.com";
     private static final String INVALID_HOUSING_TYPE = "AAA";
+    private static final String INVALID_BUDGET = " ";
     private static final String INVALID_TAG = "#friend";
 
     private static final String VALID_NAME = ALICE_BUYER.getName().toString();
     private static final String VALID_PHONE = ALICE_BUYER.getPhone().toString();
     private static final String VALID_EMAIL = ALICE_BUYER.getEmail().toString();
     private static final String VALID_HOUSING_TYPE = ALICE_BUYER.getHousingType();
+    private static final String VALID_BUDGET = ALICE_BUYER.getBudget().toString();
 
     private static final List<JsonAdaptedTag> VALID_TAGS = ALICE_BUYER.getTags().stream()
             .map(JsonAdaptedTag::new)
@@ -41,7 +44,8 @@ public void toModelType_validBuyerDetails_returnsBuyer() throws Exception {
     @Test
     public void toModelType_invalidName_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(INVALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = Name.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
@@ -49,7 +53,8 @@ public void toModelType_invalidName_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidPhone_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(VALID_NAME, INVALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = Phone.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
@@ -57,7 +62,8 @@ public void toModelType_invalidPhone_throwsIllegalValueException() {
     @Test
     public void toModelType_nullPhone_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, null, VALID_EMAIL, VALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(VALID_NAME, null, VALID_EMAIL, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Phone.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
@@ -65,7 +71,8 @@ public void toModelType_nullPhone_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidEmail_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, INVALID_EMAIL, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = Email.MESSAGE_CONSTRAINTS;
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
@@ -73,7 +80,8 @@ public void toModelType_invalidEmail_throwsIllegalValueException() {
     @Test
     public void toModelType_nullEmail_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, null, VALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, null, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Email.class.getSimpleName());
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
@@ -81,17 +89,37 @@ public void toModelType_nullEmail_throwsIllegalValueException() {
     @Test
     public void toModelType_invalidHousingType_throwsIllegalValueException() {
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_HOUSING_TYPE, VALID_TAGS);
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, INVALID_HOUSING_TYPE,
+                        VALID_BUDGET, VALID_TAGS);
         String expectedMessage = "Housing types can only be HDB, Condominium or Landed.";
         assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
     }
 
+    @Test
+    public void toModelType_invalidBudget_throwsIllegalValueException() {
+        JsonAdaptedBuyer buyer =
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE,
+                        INVALID_BUDGET, VALID_TAGS);
+        String expectedMessage = Budget.MESSAGE_CONSTRAINTS;
+        assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
+    }
+
+    @Test
+    public void toModelType_nullBudget_throwsIllegalValueException() {
+        JsonAdaptedBuyer buyer =
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE,
+                null, VALID_TAGS);
+        String expectedMessage = String.format(MISSING_FIELD_MESSAGE_FORMAT, Budget.class.getSimpleName());
+        assertThrows(IllegalValueException.class, expectedMessage, buyer::toModelType);
+    }
+
     @Test
     public void toModelType_invalidTags_throwsIllegalValueException() {
         List<JsonAdaptedTag> invalidTags = new ArrayList<>(VALID_TAGS);
         invalidTags.add(new JsonAdaptedTag(INVALID_TAG));
         JsonAdaptedBuyer buyer =
-                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE, invalidTags);
+                new JsonAdaptedBuyer(VALID_NAME, VALID_PHONE, VALID_EMAIL, VALID_HOUSING_TYPE,
+                        VALID_BUDGET, invalidTags);
         assertThrows(IllegalValueException.class, buyer::toModelType);
     }
 }
diff --git a/src/test/java/seedu/address/storage/JsonAddressBookStorageTest.java b/src/test/java/seedu/address/storage/JsonAddressBookStorageTest.java
index 6f279d23857..8662be6705d 100644
--- a/src/test/java/seedu/address/storage/JsonAddressBookStorageTest.java
+++ b/src/test/java/seedu/address/storage/JsonAddressBookStorageTest.java
@@ -3,8 +3,8 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static seedu.address.testutil.Assert.assertThrows;
-import static seedu.address.testutil.TypicalPersons.ALI;
 import static seedu.address.testutil.TypicalPersons.ALICE_SELLER;
+import static seedu.address.testutil.TypicalPersons.ALI_BUYER;
 import static seedu.address.testutil.TypicalPersons.HOON_SELLER;
 import static seedu.address.testutil.TypicalPersons.IDA_SELLER;
 import static seedu.address.testutil.TypicalPersons.getTypicalAddressBook;
@@ -75,8 +75,8 @@ public void readAndSaveAddressBook_allInOrder_success() throws Exception {
         // Modify data, overwrite exiting file, and read back
         original.addPerson(HOON_SELLER);
         original.removePerson(ALICE_SELLER);
-        original.addPerson(ALI);
-        original.removePerson(ALI);
+        original.addPerson(ALI_BUYER);
+        original.removePerson(ALI_BUYER);
         jsonAddressBookStorage.saveAddressBook(original, filePath);
         readBack = jsonAddressBookStorage.readAddressBook(filePath).get();
         assertEquals(original, new AddressBook(readBack));
diff --git a/src/test/java/seedu/address/testutil/BuyerBuilder.java b/src/test/java/seedu/address/testutil/BuyerBuilder.java
index 6ffc7237d8a..c11e6cc4768 100644
--- a/src/test/java/seedu/address/testutil/BuyerBuilder.java
+++ b/src/test/java/seedu/address/testutil/BuyerBuilder.java
@@ -3,6 +3,7 @@
 import java.util.HashSet;
 import java.util.Set;
 
+import seedu.address.model.person.Budget;
 import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Email;
 import seedu.address.model.person.Name;
@@ -18,12 +19,14 @@ public class BuyerBuilder {
     public static final String DEFAULT_NAME = "James Lim";
     public static final String DEFAULT_PHONE = "93840172";
     public static final String DEFAULT_EMAIL = "james@gmail.com";
+    public static final String DEFAULT_BUDGET = "666000";
     public static final String DEFAULT_HOUSING_TYPE = "HDB";
 
     private Name name;
     private Phone phone;
     private Email email;
     private String housingType;
+    private Budget budget;
     private Set<Tag> tags;
 
     /**
@@ -34,6 +37,7 @@ public BuyerBuilder() {
         phone = new Phone(DEFAULT_PHONE);
         email = new Email(DEFAULT_EMAIL);
         housingType = DEFAULT_HOUSING_TYPE;
+        budget = new Budget(DEFAULT_BUDGET);
         tags = new HashSet<>();
     }
 
@@ -45,6 +49,7 @@ public BuyerBuilder(Buyer personToCopy) {
         phone = personToCopy.getPhone();
         email = personToCopy.getEmail();
         housingType = personToCopy.getHousingType();
+        budget = personToCopy.getBudget();
         tags = new HashSet<>(personToCopy.getTags());
     }
 
@@ -80,6 +85,14 @@ public BuyerBuilder withHousingType(String housingType) {
         return this;
     }
 
+    /**
+     * Sets the {@code Budget} of the {@code Buyer} that we are building.
+     */
+    public BuyerBuilder withBudget(String budget) {
+        this.budget = new Budget(budget.trim());
+        return this;
+    }
+
     /**
      * Parses the {@code tags} into a {@code Set<Tag>} and set it to the {@code Person} that we are building.
      */
@@ -89,6 +102,6 @@ public BuyerBuilder withTags(String ... tags) {
     }
 
     public Buyer build() {
-        return new Buyer(name, phone, email, housingType, tags);
+        return new Buyer(name, phone, email, housingType, budget, tags);
     }
 }
diff --git a/src/test/java/seedu/address/testutil/PersonUtil.java b/src/test/java/seedu/address/testutil/PersonUtil.java
index 175b79f5147..f6305645520 100644
--- a/src/test/java/seedu/address/testutil/PersonUtil.java
+++ b/src/test/java/seedu/address/testutil/PersonUtil.java
@@ -1,6 +1,7 @@
 package seedu.address.testutil;
 
 import static seedu.address.logic.parser.CliSyntax.PREFIX_BLOCK;
+import static seedu.address.logic.parser.CliSyntax.PREFIX_BUDGET;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_EMAIL;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_HOUSING_TYPE;
 import static seedu.address.logic.parser.CliSyntax.PREFIX_LEVEL;
@@ -18,6 +19,7 @@
 import seedu.address.logic.commands.EditCommand.EditPersonDescriptor;
 import seedu.address.model.house.House;
 import seedu.address.model.house.NonLanded;
+import seedu.address.model.person.Buyer;
 import seedu.address.model.person.Person;
 import seedu.address.model.person.Seller;
 import seedu.address.model.tag.Tag;
@@ -30,8 +32,8 @@ public class PersonUtil {
     /**
      * Returns an add command string for adding the {@code buyer}.
      */
-    public static String getAddBuyerCommand(Person buyer) {
-        return AddBuyerCommand.COMMAND_WORD + " " + getPersonDetails(buyer);
+    public static String getAddBuyerCommand(Buyer buyer) {
+        return AddBuyerCommand.COMMAND_WORD + " " + getBuyerDetails(buyer);
     }
 
     /**
@@ -56,6 +58,22 @@ public static String getPersonDetails(Person person) {
         return sb.toString();
     }
 
+    /**
+     * Returns the part of command string for the given {@code buyer}'s details.
+     */
+    public static String getBuyerDetails(Buyer buyer) {
+        StringBuilder sb = new StringBuilder();
+        sb.append(PREFIX_NAME + buyer.getName().fullName + " ");
+        sb.append(PREFIX_PHONE + buyer.getPhone().value + " ");
+        sb.append(PREFIX_EMAIL + buyer.getEmail().value + " ");
+        sb.append(PREFIX_HOUSING_TYPE + buyer.getHousingType() + " ");
+        sb.append(PREFIX_BUDGET + buyer.getBudget().value + " ");
+        buyer.getTags().stream().forEach(
+                s -> sb.append(PREFIX_TAG + s.tagName + " ")
+        );
+        return sb.toString();
+    }
+
     /**
      * Returns the part of the command string for the given {@code seller}'s details, including houses.
      */
diff --git a/src/test/java/seedu/address/testutil/TypicalPersons.java b/src/test/java/seedu/address/testutil/TypicalPersons.java
index 6a438d9f008..b08a4c34f61 100644
--- a/src/test/java/seedu/address/testutil/TypicalPersons.java
+++ b/src/test/java/seedu/address/testutil/TypicalPersons.java
@@ -1,13 +1,19 @@
 package seedu.address.testutil;
 
+import static seedu.address.logic.commands.CommandTestUtil.VALID_BUDGET_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_BUDGET_BEN;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_BUDGET_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BEN;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_EMAIL_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_HOUSING_TYPE_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_HOUSING_TYPE_BEN;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_HOUSING_TYPE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_AMY;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BEN;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_NAME_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_AMY;
+import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BEN;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_PHONE_BOB;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_FRIEND;
 import static seedu.address.logic.commands.CommandTestUtil.VALID_TAG_HUSBAND;
@@ -68,7 +74,7 @@ public class TypicalPersons {
             .withEmail("heinz@example.com").withHouses(new NonLanded(new Block("10F"), new Level("21"),
                     new PostalCode("654326"), new Street("Orchard Street 5"), new UnitNumber("150"))).build();
     public static final Buyer ALICE_BUYER = new BuyerBuilder().withName("George Best").withPhone("9482442")
-            .withEmail("heinz@example.com").withHousingType("HDB").build();
+            .withEmail("heinz@example.com").withBudget("333000").withHousingType("HDB").build();
 
     // Manually added
     public static final Seller HOON_SELLER = new SellerBuilder().withName("Hoon Meier").withPhone("8482424")
@@ -92,17 +98,28 @@ public class TypicalPersons {
             .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND).withHouses(HOUSE3).build();
 
     // Manually added - Buyer's details found in {@code CommandTestUtil}
-    public static final Buyer ALI = new BuyerBuilder().withName("Ali York")
-            .withPhone("82937163").withEmail("ali@gmail.com").withHousingType("HDB").withTags("friends").build();
-    public static final Buyer BEN = new BuyerBuilder().withName(VALID_NAME_BEN).withPhone(VALID_PHONE_BOB)
-            .withEmail(VALID_EMAIL_BOB).withHousingType(VALID_HOUSING_TYPE_BOB)
+    public static final Buyer ALI_BUYER = new BuyerBuilder().withName("Ali York")
+            .withPhone("82937163").withEmail("ali@gmail.com").withBudget("400000")
+            .withHousingType("HDB").withTags("friends").build();
+    public static final Buyer BEN_BUYER = new BuyerBuilder().withName(VALID_NAME_BEN).withPhone(VALID_PHONE_BEN)
+            .withEmail(VALID_EMAIL_BEN).withBudget(VALID_BUDGET_BEN).withHousingType(VALID_HOUSING_TYPE_BEN)
+            .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
+            .build();
+
+    public static final Buyer AMY_BUYER = new BuyerBuilder().withName(VALID_NAME_AMY).withPhone(VALID_PHONE_AMY)
+            .withEmail(VALID_EMAIL_AMY).withBudget(VALID_BUDGET_AMY).withHousingType(VALID_HOUSING_TYPE_AMY)
+            .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
+            .build();
+
+    public static final Buyer BOB_BUYER = new BuyerBuilder().withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
+            .withEmail(VALID_EMAIL_BOB).withBudget(VALID_BUDGET_BOB).withHousingType(VALID_HOUSING_TYPE_BOB)
             .withTags(VALID_TAG_HUSBAND, VALID_TAG_FRIEND)
             .build();
 
     // Manually added - Person's details found in {@code CommandTestUtil}
     public static final Person ALICE = new PersonBuilder().withName("Alice Pauline")
             .withEmail("alice@example.com")
-            .withPhone("94351253").withHousingType(VALID_HOUSING_TYPE_AMY)
+            .withPhone("94351253").withHousingType("HDB")
             .withTags("friends").build();
     public static final Person BOB = new PersonBuilder().withName(VALID_NAME_BOB).withPhone(VALID_PHONE_BOB)
             .withEmail(VALID_EMAIL_BOB).withHousingType(VALID_HOUSING_TYPE_BOB)
@@ -126,7 +143,7 @@ public static AddressBook getTypicalAddressBook() {
     }
 
     public static List<Person> getTypicalPersons() {
-        List<Person> typicalPersons = Arrays.asList(ALICE_SELLER, BEN, BENSON_SELLER,
+        List<Person> typicalPersons = Arrays.asList(ALICE_SELLER, BEN_BUYER, BENSON_SELLER,
                 CARL_SELLER, DANIEL_SELLER, ELLE_SELLER, FIONA_SELLER, GEORGE_SELLER);
 
         List<Person> sortedTypicalPersons = typicalPersons.stream()