Why is there a difference in Kelley Blue Book and NADA pricing?

The difference is this: it's a nasty little scheme designed to fatten corporate American while dwindling average joe's bank account. The NADA is used primarily for tax purposes...ie, vehicle registrations and of course dealer's pricing, OF WHICH YOU PAY TAXES ON!!! The Kelley blue book value of course is significantly lesser of the two because that is the price that the dealer will want to give you for your vehicle. Creating a larger profit margin for themselves.