I thought the idea of the AppCenter was a great idea, until the first time I had to pay for something.
I'm not complaining about how much, or that you want a payment, but that I can't use my PayPal.
Like it or not... this is how the poor consumers of the world buy stuff. I'm more than a little bent out of shape that you'll only take credit cards.
Please add more transaction options than just a credit card.