maybe the OEM was just on sale a a great price.

anyway. I use a Vantec Aeroflow2 that I got for 25 bucks. keeps my cpu at a good temp. The best, imo would be the thermalright series of heatsinks. heavy bishes, but they disperse the heat well and you can choose multiple fan sizes/speeds. bigger fan to keep it quiet and cool. Be sure to check their website to see if your mainboard is compatible with the heatsink before you buy it, though. It's so heavy that you need to use the mainboard holes to secure it with some screws. I've heard nothing but great things about that manufacturers heatsinks. I'm buying one next time I upgrade, which shouldn't be too far off. heh.