Supply and demand.That’s it.
App stores, at the end of the day, are marketplaces. On marketplaces, prices are set by supply and demand.
Right now, supply is low (not too many apps) and demand is high (plenty of people are starting to play with it).
As supply increases, competition will drive prices down. And this even though some apps are discounted for the store’s launch.
Just in case you were wondering.