[falcolas]

Except, the new user isn't paying $20 at once, they pay $10 to the app store to buy the app, then they have to pay $10 at a later point inside the app to enable new features.

Same problem. The new user has a poor experience, and essentially pays twice for features that were bundled in the app to begin with.

Of course, at the $10 price point for initial purchases and upgrades, it's simpler to just release a separate app.