The "fool and his money are soon parted" is an old term stretching back to the 1500's, and I meant no offense by it. I should have phrased that better and not jumped to the assumption that everyone is familiar with such old sayings, since we're such a worldly bunch on A.org, locationally. Apologies if any offense was taken, none was intended in the least.
To the fellow that's considering purchasing a rather expensive OS4 machine, there's a lot to absolutely love about them, but as the others have said, it'd be a shame to see you invest such an ungodly sum of money into a PC that doesn't do what you hoped it would.
I'd recommend just getting WinUAE (or Amiga Forever, since the ROM's are there for legacy stuff anyways) and a copy of OS4 FE. It won't be the ideal experience true hardware would be, but should give you a fair enough peek into things for under 50 bucks total, which sure beats a $3000 investment. I'd be leery of buying any OS4 machine atm to begin with, with the X5000 coming out in the future.
In the end, if the software you want to run on said OS4 PPC machine hits or otherwise requires the authentic hardware like the old custom Miggy chips, the NG box will no more have said chips in it than a Best Buy special Windows PC would, leaving you in emulation land anyways.
MOS machines are dirt cheap, and tbh - I always found MOS to handle legacy software a wee bit better than my SAM does.