Some people here seem to be responding to all of this inappropriately. The simple fact is that Apple is injecting itself as an intermediary in the payment process and extracting a preposterously oversized commission for no meaningful added value. And it's easy to see that Apple knows what they're doing is wrong. They strictly prohibit developers from signaling that there's an extra cost for purchases made through App…
I don't disagree. But you do realize you could also be describing the credit card market?
The same fate will probably befall Apple, too.