@sbullock, you forgot one, “Pay Once and Play” My app made more the $50.00 with this model(not much more lol). Also, Apple is starting to promote this revenue model
People are slowly getting fed up with freeium apps because they end up paying and paying.
But definitely don’t invest more then 500.00$ on any app, you will probably never even make that money back. If you look at the guys who made money from any app Look at what else they made – you’ll see they made 15-20 apps!. So, your first 10-15 apps might have to chalk up to experience. You have to pay your dues.
That’s why Corona is so awesome, its free.