Erm...
Heatercore, like a Fedco 2-342 - $25 @ Auto Parts Store
DD TDX, Swiftech MCW6002, etc. CPU waterblock - $60
Eheim 1048 - $55
or Hydor L20 - $40
Tubing, Clamps - hardware store - $10
2x120mm fans for heatercore - $20 or scavenge
$5 to $20 over but it's a quick and dirty estimate. Look for deals on fans or pumps on ebay or elsewhere.