bought my dreamcast off of ebay for $25 (included shipping) ... got a feb 2000 dc, 2 sega controllers, 1 sega vmu, 1 sega jump pak, and 2 games (dead or alive 2 & sega bass fishing)
usually if you ask the seller they will tell you the manu. date, but it is like anything else on ebay.... buyer beware :)