Help with if/then calculations

Hello out there!

Ok, so I know just enough to get myself in trouble sometimes and don't know how to write scripts 😕😕

I'm looking to set up a form for my business to make quick work of estimating and am trying to create what I believe to be a simple calculation as follows:

Form field 1 is a drop down named "Box Type" and may contain the following drop-down options: "Frameless; Faceframe; Inset"

Form field 2 is a text box called "Base Amount" with the Format set as "Currency", and I want that box to display a dollar amount based on the option displayed in form field 1.

Hope I've made sense here! (not meant to be condescending to anyone on this forum, I just dont know that I've stated my request properly)