PayJunction: Calculate a payment value based on selection

I need the Pay Junction app on my form updated to the value of Single Choice Element. For example, when the user selects 1st,2nd,3rd, or 4th Grade, a predefined single choice question worth $50 appears. When the user selects next, I need that to show $50 on the next payment page for Payjunction. How do I do this?

Yes this is possible.

First add your single choice field. Open its properties (gear icon). Label your options, and add calculation values for each selection.

Then add a form calculation widget. Open its wizard (magic wand icon) and add the single choice field.

Finally add your payjunction integration. Open its properties, and specify a user defined amount. Then select your form calculation widget as the "get price from" option.

Full instructions here:

How-to-Pass-a-Calculation-to-a-Payment-Field