That is exactly what I mean. If a developer increases the major version with a serious update on features, redesign, ... It would be nice to be able to offer th

That is exactly what I mean. If a developer increases the major version with a serious update on features, redesign, ... It would be nice to be able to offer these for an update-price, cheaper for existing customers but normal prices for new users. With the current model for app updates you risk to loose and disenfranchise your loyal customer base if you create a whole new app that users can't simply update to or you have to maintain support for users that paid $2 once.