Right, but that stops there

At 1.2$ you already earn more then the Apple Store.

    $ 1.0 Apple: 0.7 Stripe: 0.671
    $ 1.1 Apple: 0.77 Stripe: 0.7681
    $ 1.2 Apple: 0.84 Stripe: 0.8652

So just make it 1.49 and you are good (you'll earn a full 10% more than with Apple)

Anyway even at 0.99 price tag (I think Apple doesn't allow 1$) it only 4.5% less, on a million unit sold the difference would be about 31,710 dollars (693,000 VS 661,290).