If you want just the pump here is one
for only $40 bucks plus shipping. Or you might like this one for only $40
, (I do). If you want a factory sealed CPU unit which is a very good, quick and simple way to go (and your not planning on overclocking or overclocking much) it will run you anywhere from $80 to $120. I'll put links up to them if you like but I'm just linking what you asked for first.