I downloaded it and tried it. It works great so far. I tried it with a huge balance and it subtracted everything correctly. I also tried it with 0 credit and it worked fine.

The only thing this feature needs is to allow the purchaser the ability to not have to put in a payment type if the balance owed is $0. At the least, maybe some info that says that they will not be charged even though they need to input there card info.

Anyone got any ideas?

Corbett