Also:
> It baffles us why a larger sale should cost more than a smaller sale. The storage and transfer of an digit or two on a computer is negligible.
Represents a massive misunderstanding of what a credit card company charges for. A larger payment represents a larger risk if the payment is never received or is received fraudulently. It's one thing if $5 is fraud. It's another if $5000 is fraud and needs to be returned. You're not paying someone to move bits around, you're paying someone to take the risk that someone could issue a chargeback and demand their money returned.