Good price if the shipping is fair. Eventually these fans will need a drop of oil on the sleeve bearing.
From the $6 slot fan post of 4/7:
NEXFAN.COM has this for $2.99 (3.99 now on 4/17) with $6.99 flat shipping per order (so load up on some other stuff too). The black ones, at $2.99, may be a little better by design (using all exhaust slots in the bracket). Good outfit. I run them next to oc'd GF4ti4200 & GF3 cards in uATX boxes. They pull lots of heat from the case. Great for uATX cases that don't have good ventilation.
Modifications:
Cut out the plastic grill over the air intake (it is pointless).
Consider rewiring the plug for 7V operation, slower but quieter.
If the fan is only blowing out of 1/2 the slots on the bracket then cut away 1" of plastic baffle within the housing.