Sure, in those cases you consume more resources, but those are probably negligible compared to the increase in price. The reality is that they charge you more because you make more money from the service, hence you are willing to pay.

It's not precisely the same, obviously. For one, you can chose the services you want, while you must go through Apple's App Store. And since they don't charge a percentage of revenue but charge for resources, you don't see the correlation.

But the final effect is the same. The more money you make, the more you pay.