Best Hardware-per-$ for fast lighting builds

If I wanted to radically speed up my lighting builds without going into bankruptcy, what should I look for in hardware? Does Enlighten scale to 16 or 32 or even 64 cores?

If it scales, perhaps a 2 x 16-Core Opteron 6282 SE (2.6 GHz) system might do the trick? Two CPUs should be about $300 on eBay, plus another $500 for an overpriced dual CPU server motherboard.

If it doesn't scale, I could also opt for an Intel system, like 2 x 12-Core Xeon E5-2697 v2 (2.7 GHz). However, even if that was 2x the speed of the AMD system, it would cost 10x as much :-/

What is everyone else using to cut down the waiting time for lighting to build?

 

I have to admit I'm curious now. I've found slightly slower 16-Core Opteron 6276 (2.3 GHz) CPUs for $60 each on eBay and a Dell PowerEdge C6145 Motherboard (Quad CPU) for $90 on eBay.

 

Nice, an affordable quad CPU motherboard. I had only seen the Supermicro H8DG and the Asus KGPE, both quite pricey. Those 460 Watts (4 x 115W TDP) may up the energy bill, though

Just found this thread: Bake Enlighten faster?

(EDIT: 115W TDP, not 140W)

 

I bake cycles textures on the gpu, nuff said.