Hi @Holly_CMS ,
Do you have such an error?

This is because currency column is number column in SharePoint, only numbers can be saved.
To avoid this error, need to make the saved data is number. You can set the 'Update' of the Card in the form so that the content of the submission is only numbers.
I made a sample for you.
Create a list in SharePoint, and ‘ESTCost’ is a currency column.

Create a form and set the Textinput ‘DataCardValue8’ to the following format:
"$" & Text(ThisItem.ESTCost,"0.00")

Set the Update of the Card. Only the content after the symbol '$' is submitted.
Value(Mid(DataCardValue8.Text,2))

After testing, no error is reported:


Best Regards,
Wearsky