[atishay811]

I think what it will eventually turn out to be is - Apple will require IAP/Storekit but will be forced to allow others. And you will see something like this - $10 - Pay by Apple, $8 Pay via Amazon/Google/Whoever big name enters this business, $7 pay by credit card directly. And you can chose if you need Apple's unsubscribe, want to trust Amazon for $2 discount, or want to get a further $1 discount by entering your credit card number and risking doing a chargeback in the future if the developer is really crappy.

Eventually Apple will get down to make the Amazon not turn profit out of iOS IAP and then you will be left with two choices.