I just bought a used Cannondale warrior 1000, I belive this bike is a 2002 model. Anyway, the bike had 43 miles on the ODO, looked like bran new, the tires were not even worn at all. I got a like brand new bike for half what it would cost new. I think as long as the brakes are good, the bike is in good shape and the bike doesn't have any problems shifting or anything, there is no problem with buying it used.
No in my opinion anyway, I am always looking for a way to save money. LOL