AROS gets a lot more bounty money. It has a lot more developers working on it.
Why not switch?
The retro collectors are happy paying a thousand for an Amiga with low power, but people trying to use them are as sad as can be. (Because of limited software or incompatibility).
I flipped off Windows Vista and Windows 7 because I can't stand them and there was incompatibility with a lot of my software.
You should consider porting the handful of programs that you need to AROS.
Even if Power PC trundles along the market is so small the machines will continue to be very expensive. To me not worth the money.
I can have AROS on my x86 machine (free) and also a powerful classic Amiga no more than $500 in cost (with 030 or 040).