docs: add cost estimation (closes #57) (#59)

README.md

@@ -165,6 +165,10 @@ Note that the documents are uploaded automatically when deploying the sample to
   - Your Azure account must have `Microsoft.Authorization/roleAssignments/write` permissions, such as [Role Based Access Control Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#role-based-access-control-administrator-preview), [User Access Administrator](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#user-access-administrator), or [Owner](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#owner). If you don't have subscription-level permissions, you must be granted [RBAC](https://learn.microsoft.com/azure/role-based-access-control/built-in-roles#role-based-access-control-administrator-preview) for an existing resource group and [deploy to that existing group](docs/deploy_existing.md#resource-group).
   - Your Azure account also needs `Microsoft.Resources/deployments/write` permissions on the subscription level.
 
+#### Cost estimation
+
+See the [cost estimation](./docs/cost.md) details for running this sample on Azure.
+
 #### Deploy the sample
 
 1. Open a terminal and navigate to the root of the project.

docs/cost.md

@@ -0,0 +1,13 @@
+## Cost estimation
+
+Pricing varies per region and usage, so it isn't possible to predict exact costs for your usage.
+However, you can use the [Azure pricing calculator](https://azure.com/e/a5769032546440dc98285eaba6bd5423) for the resources below to get an estimate.
+
+- Azure Functions: Consumption plan, Free for the first 1M executions. Pricing per execution and memory used. [Pricing](https://azure.microsoft.com/pricing/details/functions/)
+- Azure Static Web Apps: Free tier, 100GB bandwidth. Pricing per GB served. [Pricing](https://azure.microsoft.com/pricing/details/app-service/static/)
+- Azure OpenAI: Standard tier, GPT and Ada models. Pricing per 1K tokens used, and at least 1K tokens are used per question. [Pricing](https://azure.microsoft.com/pricing/details/cognitive-services/openai-service/)
+- Azure AI Search: Basic tier, 1 replica. Pricing per hour. [Pricing](https://azure.microsoft.com/pricing/details/search/)
+- Azure Blob Storage: Standard tier with LRS. Pricing per GB stored and data transfer. [Pricing](https://azure.microsoft.com/pricing/details/storage/blobs/)
+
+⚠️ To avoid unnecessary costs, remember to take down your app if it's no longer in use,
+either by deleting the resource group in the Portal or running `azd down --purge`.