I disagree. Take a bare minimum of 15%. That seems to be about what's competitive for non-merchant-account payment systems. You'll need to keep margins up.
Exactly. And keep in mind, you're competing against someone setting up their own web store. If I didn't use your service, I probably wouldn't go through all of the trouble of setting something up. In that scenario, I make $0. If you charge 30%, and I price my stuff at $10.00, I make $7 per transaction, which is $7 more than I would have made without your service.
