It works and its free :)

works well!

i do miss a function in which i can add a conditional fee multiplied by the number of a specific product. for example, product A has a fee, product B has no fee. I buy 5 units of product A and 1 unit product B, at this point multiply the fee by 5.

what i ended up doing with your system is making a fee for every option (!) – i had to make 100 different option just in case somebody at some point would order 100 units of my product. if someone ever orders 101 units they will get around the fee all together…