I think if you want an RTG Amiga with AGA for games and stuff like DPaint, Brilliance, Scala, then the A4000 is the best choice..
Umm why do you need RTG for the apps you mentioned? They actually work nicely with AGA so would be fine on an A1200.
As far as pricing in usa for an a4k if you want a nice cared for white one, working nicely i'd say $400-500 + to be realistic
