I've been doing this sort of thing for 20 years now, ever since I had a 286 with 1 meg of ram. It's sort of like drag racing computers. I really like doing this and I get promo boards from some manufactures just to test them, so that does cut the costs a bit. There is also a lot of swapping and trading going on in the overclocking forums. I build phase change units for people and that makes money too $$$$. Here's a couple pics of one unit that is now running right next to me. The unit uses 2 rotary refrigeration compressors and it is all fitted into a nice sound proofed box. The 2 braided lines have evaporators on the ends that are clamped to the cpu and video cpu's (crossfire, x1950xtx). The whole unit in box weighs about 75 LBS.