Even from a tinkerer hobbyist standpoint. The $$ amount of electricity used to run that Amiga rig over time vs. 3D rendered output just doesn't add up.
I'm not so sure about that, these 64bit processors use up to 130w for the processor alone whilst the whole PC probably has a PSU supplying a minimum of 500watts.
Most of that power is turned into heat, not MIPS.
On the other hand a 1200 uses a 23watt psu. and since PCs are never turned off, the Amiga is better for the Environment.
And in the future its performance can be bolstered by an FPGA to possibly match or outperform the PC.