I'm seeing them at Directron.com with the order of a case and power supply
1 for $4.99
2 for $9.98

Is this the cheapest you have seen them?

My favorite place this week: SVC

http://www.svc.com/zaladfanspee.html

Newegg sells them at that price, without the prerequisite case and PSU purchase.

Pricewatch says Best Byte sells them for $4.25 apiece, and you can get as many as you want for $5 ground shipping from Texas (shipping is total, not apiece).

Edit: wow, SVC to the rescue! Screw Best Byte and Newegg.

Best Byte is the cheapest that I found with a fix shipping charge of $5. The problem I have with them is that it took over a week for my order to get to me. If you don't mind the wait, they are the way to go.

And for those in europe, http://www.pc-look.com sells them for €3.79, and ships to BE,DE,ES,IT,LU,NL,AT,CH,DK,FI,GB,IE,PT,SE, for €8.12.

or, if you're going to run your fans @ 5V, you can just buy the zalman multi-connectors...i did it and it works for me!