I think it can be done for about 60. Prices may have changed though.

i need to do the math and see if i can get away with having no active cooling for the radiator. The cpu is something like 25-35w tdp and the entire nas is only cooled by 2 60m fans

That's possible. You could just place the rad behind the fans to get some amount of airflow.

i really need to think it through properly since there isn't too much room for anything. If i can get away with the block under one of the hdds and the rad next to that hdd to get some airflow, it could work. The fact that i have a 5th ghetto mounted drive in the nas (for the os) really reduces my available space for the pump. I basically need a rad with the approx formfactor of a 3.5" drive, a low profile waterblock and a fairly small pump. And tubing thin enough that it can handle the flow and still fit in the small space. I smell a trip to the hardware store

huh. Doable under $25 as long as i secure the tubing with zipties inatead of fittings. I am impressed.

40*40*15 block, 200ml res and 80mm rad

That's pretty cool! No pun intended. I may do that with an HD6850 at some point.

i'll come back with a list when i get home. 4g is choppy on the train