I would pay for a decent AA title that would come in a oversized box and on disks, the price wouldn't be for the time the game took as that should be done for the love of programming and the Amiga, but to cover the production of the box, manual, disks etc and obviously a little for themselves, it's never gonna make anyone any money but surely no retro games do.....other platforms have them, it's strange with the amount of followers the Amiga isn't one of them.
How long since the last A500 boxed game? 1999, 2000? I'm not sure exactly but it's a long time.
I would pay for any new game that's decent enough, even unreleased games that have been given the go ahead to release and made box etc for.
Heck I'd pay for Putty Squad in a box and on disks to experience a new disk game for over a decade or more!