Set up CC processing on the web:
How much are you going to pay stripe? 2.9% + 30¢ ... that means you have to charge 10 bucks to get down to a 6% transaction fee. Quite the price floor and an interesting cap on your pricing model!
What does managing chargebacks cost you? The moment your taking money your going to hire in customer service, or spend time dealing with CS. What happens when you get a chargeback, or do a refund? Most of the time you loose money (processing fees etc)
If your under a million bucks a year apple is 15%. If you're building a low price app or a value add app, odds are that apple is going to be a far better deal for you than doing it on your own.