Cost of the same item is different depending on payment type

I’m going to try to keep my annoyance to a minimum, but this is bizzare. not only is there no option to split the payment between bnet balance and other payment method for some reason which at a minimum is an annoyance requiring calculating the exact balance needed to make a purchase without having bnet balance leftover. but apparently the calculation of taxes is different between the credit card for example and bnet balance. where bnet balance charge is a few cents higher AFTER you already purchase the rest of the balance, and because a minimum purchase is $5, you are now stuck with balance that is JUST under what you need and purchasing $5 is leaving you with extra useless bnet balance… AGAIN.

this is wrong. this should NOT be working this way. I should be able to just make a purchase, have ZERO balance on my account the way it works with EVERY. OTHER. GAME. SHOP. ON THE MARKET.

FIX this.