I think it makes things a little tough when you see on-line ads for new 2013 models at $45,000. These could be stripped down models but people look at that number and may view $39,900 as not much of a bargain for a two year old unit. If you figure a -20% loss in value as soon as you drive a new unit off the lot and then another -10% reduction/year after that I'm thinking you'll need to be at the NADA low end ($34,000) to sell the unit quickly.
What was the dealer offer?
2012 KZ Spree Escape E204S
2007 Chevy Silverado 1500 4.8L, 3.23