Conditional Formatting of a drop down field on an order form

Hello! I'm trying to create an apparel order form that will calculate the total amount of all requested fields. The calculations appear to be working in the right hand table for each size "Amount" and overall "Total". The glitch I'm encountering is that the dropdown selection for "Add school logo" also needs to be factored into the equation - there will be a "yes" and "no" answer available from the drop down. If "yes" then $5.00 needs to be added to the amount/total boxes. If no, then the amount would remain as is. My experience with calculations is minimal so not sure how to best proceed.

Thank you for any guidance!