So Apple won't accept the ebooks directly? Huh.
I think you're probably right about old vs new. But it's probably not the procedures so much as its the mentality. As I understand it, the payment procedure is automated (or at least it should be). The actual cost of processing a payment is negligible (which is why Amazon set it so low).
I'd guess that the other companies still think of the cost as being the same as when it was done by hand. That was expensive when compared to doing it by computer.