@dlehenky, Certainly the curiosity of exploring technical and economic horizons is a big one. Even with 2nd hand system gear, a system is still going to cost $100 ~ $200 but obviously if someone just trying to get a look in, already has a slot limited mobo, then $30 bucks could let them realise a 6 GPU rig.
Depending on what limits turn up, such as the 8 GPU bios limit I'll be running 6 370's on a 1200w (Silverstone strider gold) and the system with another 2 GPU's on an 850w Gamemax.
If I find what the actual kernel hack was, or some other method (which I have a low confidence of doing) then I'll try 10 GPU's with 2 of the Silverstones (and then I'm well on my way to concentrating a centralised point of failure )
I wasn't aware of any problems binding PSU's. What's you're experience?