Actually a decent 500w power supply will be arround 70$ or higher. The cheap ones are cheap for a reason , it's be cause there not very good units. There not 80+ cert and usually don't have enough amps on the 12v rail.
This is about the cheapest 500w thats a good unit on newegg.
http://www.newegg.com/Product/Produc...82E16817703015
And the cheapest 9600
http://www.newegg.com/Product/Produc...82E16814500083