Trade values are rarely great, and no one here is going to be an expert on your trade.
Another kicker right now, of all things, is that SUV values are the lowest of all, because of gas, etc. and people trending more towards smaller and lighter.
If you want the most realistic figure, go here and post:
http://townhall-talk.edmunds.com/direct/view/.ee9c851
We had an '02 Avalanche before and traded that for an '04 Suburban back in 2004. The Avalanche had 33k on it, and in flawless shape, we got $21k on trade--EXACTLY the Edmunds.com Excellent value. Then a couple of weeks ago, at the same dealer and same salesperson, we traded the Suburban with 56k on it for a new '08 Malibu. Edmunds here was $14,750 and KBB at $15,900. In the same condition as the Avalanche, we got $11k for it. Really low, but back in November we had 2 dealer back to back offer $12k, so it wasn't unexpected.
This was based all on auction and other similar used Suburban prices right now, plus wanting to put a new set of tires on for around $500. They put the Suburban on the lot for more, of course, but I know will end up selling it for $2-2.5k over what they gave us at most. Disappointing, but got a fantastic deal on the new car, the dealer is great, and realistically I knew it wasn't going to go any higher.
So...in my best guess, I'm going to say expect $13-14k for it. Low miles and great shape help, but when the same vehicle can still be had in great supply at auction, other dealers, etc. and isn't a huge hot seller in the market as it is, top KBB value is not it.
Still, go to a dealer and see, and bargain (the Outlook really isn't selling that well, and some people have actually gotten the "un-Saturn" dealer discounts and such on some new ones), and see what they offer. Also, to help yourself understand, try out the Edmunds link above and see what the many used car manager's there say for it.