Update the call to formatCurrency to eliminate warnings in the plans page

[southp]

Currently there are loads of formatCurrency warnings when visiting any page with the plans grid, e.g. the following screenshot was taken from the logged-in /plans:

The warning is meant to highlight the calls that should be updated, so let's update the call accordingly to eliminate the warnings.

[jeyip]

The warnings should be gone now #95369

[jeyip]

I created a follow-up issue to investigate why the add-on cost calculations are re-rendered dozens of times for identical return values, even though the logic is memoized #95416