Background: I'm using Foxycart w/ Foxee
Our store currently sells both books and tshirts. Our problem is that books can ship via media mail and tshirts can't. We'd like the customer to have the option to ship via media mail only if they have just a book in their cart. If they have a tshirt and book (or just a tshirt), media mail should not be an option.
I'm not quite sure how to start this one, any help would be great!