Cooler Master SickleFlow 120mm Silent Fan $3 at Newegg

Here they tests as a water cooling radiator fan lambasting it for misleading specs, though might be a decent as a standard case fan but remember it only a sleeve bearing.
http://www.anandtech.com/show/6177/choosing-the-best-120mm-radiator-fan-testing-eight-fans-with-corsairs-h80

Here it shows a good mix of low dBA to cooling, ending up mid pack.
http://www.overclockers.com/65-fans-tested-megahalems/

I agree with Casecutter. Just upon reading the description it was highly suspect that a 120mm fan spinning at only 2000 RPM could put out almost 70 CFM. That is probably not physically possibly.

Yeah, not sure how Coolermaster can make their static pressure claim, fans like this with narrow non-overlapping blades always have poor static pressure per RPM, best use being unfiltered case intake or (remotely mounted filtered or unfiltered) case exhaust w/o a radiator or stamped out /case wall perforations.

It's also a bit ironic that in the Anandtech tests, it turned out the stock fan included with the cooler turned out to be one of the best alternatives.

An axial 120mm wide fan can produce about 70 CFM at 2000 RPM, but only if thicker than 25mm. See model 4312 M & 4312 GM that produce 82.4 CFM @ 2300 RPM. It should be noted that they are 32mm thick and that while cheaper fans can match this, the model I'm mentioning usually goes for around $25 plus shipping.

http://www.ebmpapst.us/allpdfs/4300.pdf

It should also be noted that if you try to undervolt a fan like this Papst very much, it'll start making an annoying ticking sound that is worse than the noise from turbulence at higher RPM, unless your undervolt method includes strict current limiting rather than just a resistor, PWM or linear voltage control.

the reason why its cheap is cause they fail early.

You can get a fan like this to run a lot longer if you periodically relube it with a couple drops of oil, assuming it still has the removable rubber bung to do so instead of being permanently sealed.

^ or just the sticker

dave, do you use 3in1 oil?

Try sewing machine oil... It has a lower viscosity..

5W20 oil if lubed before it starts making noise, 30wt if it ran dry enough to start making noise and wore the bearing. If it wore the bearing so much that it seized up you need even more viscous oil to displace the gap in the bearing though at that point I'd only revive the fan long enough to wait on a replacement in the mail.