we've never had a problem selling a used TT on Craig's list. I think it's important to make sure its really clean, shiney on outside and clean on the inside (my wife makes sure of that even when we're camping). We've gone thru about 4 used TT's in the past 4 years and each one sold within 3 weeks of posting the ad, one of them within one week, and got asking price. I'm always surprised cause I figure it'll never sell.
Also never had a problem with a local dealer working on my unit even though I didn't buy it there. If they give you good service they figure you might buy your next one there.