how do i create a system of entering a code in one cell to insert a text string in another

i have added a couple of different concepts. Can this be done this way? I want to add features to a product based on size and other features based on price i.e. this item can be tinted for a 4% premium and this item can be enhanced for $3 per square ft. I tried to do the percentage formula but it isn't doing what i hoped.

I am working from the sheet named proposal source and working on Proposal sheet.

any help would be great!