Think about it: Suppose you own a 98 GTS which you bought new, and you've babied it's entire life. It's in excellent condition and has, say, 9000 miles on it. Never been wrecked or abused. (Well, OK, maybe once or twice you did a burnout!) You're thinking it might be nice to move on to an SRT. You decide to sell the 99. What do you sell this car for? Last time you looked, Dodge wasn't building anymore GTS's. There aren't any new ones on the market. And the number of excellent one-owner cars like yours shrinks daily. Do you (A) "give away" this car on Ebay for $40,000? Or maybe less, like some posters would like you to believe? Or (B) say screw it, I'm asking $53,000 and will let someone beat me down to $50,000? I'll bet on (B) every time unless there's a need for quick liquidation.
There is no incentive in either party in a used car sale to tell the truth about the sale price. If you're the buyer, you certainly want to look like you got a steaming deal and you weren't a dumb sh*t and paid too much. So you forget about a few thousand bucks. If you're the seller, you want to show that you knew what you were doing too and that you're not a dumb sh*t who doesn't know what his car is worth. Therefore, you embellish the sale price. So take the numbers you hear on a Viper sale with a 50-lb bag of salt.