A stock A1200? You really want something to feel like a stock A1200?! How far do you take that?
It's a cost/benefit thing. Some of the Amiga 060 demos don't run well unless you use WinUAE. So there is a very narrow window of software that is worth spending all of that money on.
Different people have different priorities. Imagine the insane price it would get to if everyone was trying to upgrade to the max.
