the ones in my link can be bought one set at a time for $13.59
as to the cooling problem it can be solved for $1. here:
DC 12V 2 Pin Brushless Cool Cooler Fan For VGA Graphics | eBay
the amount of power this fan takes is rediculously small at around .03 amps.
(the larger 60 mm fans take .04A and .48watts. this one is only 2/3 that size, so I guesstimate .03A. small enough to put anywhere!)