Apple will let Apps redirect users to sign up for services outside the App Store
9to5mac.com
9to5mac.com
As a consumer: I dunno, using Apple for payments has a lot of consumer protections. Why would I give that up?
As a consumer: eh, Its cheaper on the website, let me but it from there. Or oh it doesnt offere apple payments, I wont use it.
I'm willing to bet that the extra subscriptions you lose out on won't make up for the 30% (15% for the first 1,000,000) you lose. Personally, if I saw tiered pricing like that, I would start looking for a competitor app.