I'm going to buy an iPod Nano and was wondering whether an extended warranty is necessary, and if so, which store offers the best service plan. Does anyone have an opinion on Best Buy vs Circuit City vs Apple Care service plans? Also, Costco told me that they extend the warranty to 2 years for no additional cost. Or I was thinking about buying a new one on Ebay since it would be a lot cheaper. If I bought from Ebay, could I still get the Apple Care? Thanks!