hk will not honor costco because its a wholesaler (well im pretty sure they wont). the 630 is nothing like the 430, and the 630 is out of your budget anyway. youll have to check their website for the specs though. onkyo is a relatively inexpensive but pretty good brand, but they do rate their power driven at 1khz instead of the spectrum of music 20hz-20khz, like hk and other high end brands do. besides that onkyo is high end too. at that price range youre gonna be looking for a deal somewhere, try a high end store that may have an open item, they usually mark them down quite a bit.