>I suppose I'd be okay with a 30% fee if Apple didn't charge us $99 to maintain a developer account

Those two things aren't remotely equivalent. $100 for a dev account is peanuts. It's there to support the iOS dev ecosystem and isn't unreasonable. It should be a non-issue. 30% of app revenue, on the other hand, equates to thousands or millions of dollars depending on how popular your app is. That actually makes a material difference.