Cost was almost nothing or I probably wouldn't have done it. With a new baby in the house, I also get stuck at home bored a lot too.
The thermal take heatsink was intended fo early athlon chips if I am not mistaken (not good enough for an athlon xp though). I got it and about a dozen other asorted heatsinks for 8$ used (all old, oddball and or obsolete stuff but great for projects like this).
Ransinks are pentium 1/2 heatsinks from them cut up 4 ways.
The foam insulation is a 79 cent foam mouse pad.
The cold plate is the copper plate from a factory amd athlon xp heatsink (it just had a copper plate attached to the bottom with screws). I have three aftermarket athlon xp heatsinks and only two athlon xp systems so it was probably never going to get used.
I already had the thermal take fan in my spare fans. The rubber bands holding the fan on are hair ties, lol, but I'll find a beter way to attach it (actually I have a round blue lit mini desktop fan that was a freebee that I might try to gut and attach).
The thermal probe is an old cheapo digital meat thermometer that I modified for use with the computer some time ago that suprizingly can actually read sub zero temps.
I have been running dual power supplies in that computer for a while now. I did buy a new second power supply but it was only 23$ with a 21$ rebate so 2$ (maddog 250 watt rated at 16a on the 12v). I really needed to replace the old second power supply anyway. It was a 350 watt deer (I know, one of the worst you could possibly buy). It had a bad habit of shuting down all the time even though it was only running fans and lights. When I attached the pelt (only a 41 watt pelt) the lights went mega dim like the ps was going to blow up or something. The new maddog should be plenty for a small pelt and lights and fans. It is made by super flower if I am not mistaken.
The dielectric grease was 6$ (I could have easilly gotten away with the 2$ tube but I didn't know how much I would need). I needed it for my car anyway as I didn't use any when I changed the spark plug wires. If you have ever spent a half hour trying to get pieces of a broken off spark plug boot out of a 6 inch deep hole to get the spark plug out you know the advantqage of using it (already went out to the car and put some on).
The only think that I did feel in the pocktet book a little was using up most of my tube of artic silver, 3$ for heatsink tape (If I use it), and 8$ for some artic aluminum epoxy (if use it). It wouldn't hurt to have the artic aluminun epoxy and or the tape on hand anyway.
Oh and the last part, the pelt was gutted out of a mini fridge. I actually have three that have been sitting in a spare parts drawer for a while now.
You can probably tell from the fact that I took the time to type all that crap in, my level of boredom right now. I really do need something more constructive to do.
Oh and on the water cooling thing, I wish I had water cooling (my cpu overclock is currently being limited by heat). I think it is a little out of my budget right now but if I get a few spare dollars I might try to rig something up. Just out of curosity, how much power does it take to run water cooling? Would that 250 watt mad dog run it (probably not)?