I avoid Aquabid because there is so much fraud on that site...lots of the sellers seem really unprofessional also. Call me a snob, but the way the auctions look put me off...too many animated GIFs, all caps and bold, garish colors...it's just so amateurish.
I'd much rather deal with a single website, such as Ken's, MsJinkzd, or Bob's Tropical fish. I've never dealt with Captain Bob's Fishtales, but have heard all good things about him, so wouldn't hesitate to buy from him.
Try putting up WTB ads on here, and definitely look for local deals...joining an aquarium society, if you have one (you should in a big area like Philly!) is also a great idea.