Why so much? I don't know.
Just Kelley Blue Booked my SE-R for shits and giggles, barely topped out private party value at 1,000 and yet if I wanted to buy a fully covered, warrantied engine from Nissan it would cost me 4,700. With the understanding that mileage and condition is a huge factor, even an excellent condition low mile SE-R won't pull in as much as the cost of a new engine. I don't really know where I am going with this, but, I think our SE-R's are worth a hell of alot more than what KBB says. Esepcially now-a-days where everyone is watching how many pennies they pour down their gas tanks.