When we bought our new motorhome, we just parked the old Class C (1986 Coachman) at the end of the driveway with a FOR SALE sign on it. Ran a couple of ads in the local Penny Saver but the guy who bought it just saw it in the driveway. Got 5 times what the dealer offered us as trade-in.
I agree with Wendy. Our last TT got dozens of responses listed in the local Dandy Dime. Sold to the second guy.
The higher the price of what you're selling, the smaller the market. If you want to reach a larger market, try eBay. I listed my motorcylce on eBay a couple of years ago and a guy from Oklahoma drove all the way here to pick it up, and I got top price which I may not have been able to get locally.
If you go the eBay route, take pictures.....lots of pictures. The more pictures you post, the more attention your ad will get. This also helps alleviate people's fear of buying a high ticket item online. Just remember to disclose everything. Good luck.