I think this is part of what is holding back iPad software. You can't charge $100 for Sketch and lose $30 when someone asks for a refund. Apple designed this around $1-$10 apps where losing $2 at volume is fine.
What is worse, is that Apple doesn't remove the app from the user's device. When you get a refund of a paid app it is on the honor system for them to delete it. It is removed from their account, so they can no longer download/update, but the installed binary is not affected.
What is worse, is that Apple doesn't remove the app from the user's device. When you get a refund of a paid app it is on the honor system for them to delete it. It is removed from their account, so they can no longer download/update, but the installed binary is not affected.