EBay often means used as well as some vendors selling clearance items there. The bids start out low and then climb and sell to the highest bid. You won't see good return policy on anything used and faulty there however.
and now i feel like even more of a dumbass because you posted the same ram in your post above mine. maybe i should just go crawl into a cave and hibernate.. :/
That pair of xms memory has a Cas Latency of 5 there. The kit with a Cas 4 sees about double that price. Are you looking strictly for performance memory or just any 2gb kit. The xms series memory isn't value ram like the A-Data at the link kof2000 just posted.