Oh, well the higher the SQ, the higher the price... Plain and simple. I don't kneed booming bass to be heard down the street, nor do I need another idiot rippin me off, so I just stick with medium grade equipment. Many will say infinity and polk are crap, but it's much better than the walmart selection... I would listen to several sets before you buy as I need to do the same with Polk MOMO's...
As for purchasing, I have bought stereo equipment from ebay and have not had one bad issue with a power seller with almost perfect feedback!!