Frys has the Enermax Magma 120mm cooling fan for $5. The usual price for this fan is around $13. The listing says one per customer but I was able to buy four at once at the store. These fans are well-reviewed. They sure beat the crappy antec ones that came with my case!
http://www.frys.com/product/7989240?site=sa:adpages%20page129%20date:022617