I wonder if you could list multiple copies of an MMO game client on an app store, with each client having a different price and providing different in-game aesthetic effects like "FooGame: Sparkly Hat Edition".

Could be an easy way to get around this limitation.

The 70c that they would get out of that sale would still be much greater than the current ARPU from ad and microtransaction supported games, and would go some way to encouraging gameplay shifts.

Apple could just increase the minimum charge to $4.99 (or its regional equivalents) if it really wanted to increase quality. A decrease in its exorbitant 30% commission would be suitable as well.