When it comes to the diesel MB's, is the blue book value really anything to go by? They always seem to go for much more than what any bluebook values show. I see some cars I am interested in, then I see them priced 3 and 4 grand more than the book value, and i have to wonder which is more accurate. I know demand plays a part, but I thought kellys considered this?

__________________
1996 E300 D
1992 300D
1990 Ford E-350 7.3 Diesel AKA "the Deep Fryer"