Rarity plane and simple. Some people feel their cars are collector gold, others see them as just vehicles. I fall in the middle. I bought my roadster 05 w/ 8.5 K original miles needing nothing for $11,900 just under two years ago. This was a steal and these cars had yet to pop up on the car enthusiats radar. Now these cars have started to become a collector item b/c of what they are, and if I were to now sell my car w/ the 13.5K miles it has on it I would ask for $14-15K for itb/c I know I own one of the cleanest examples on the road.

On cars older than 10 years the Blue book prices can't be trusted. an example is I had before this a very rare 95 Miata M edition w/ 45K original miles on it. KBB said it was worth $3500 and that was completely laughable, I ended up selling the car for $6000 and I had 5 buyers who wanted it.