I've sold 3 of my RVs through CraigsList. You need to figure out who's playing games and who's serious. As mentioned be smart how your price it, do your homework on other similar units, NADA, etc. If you owe more then it's worth get a loan to pay the difference. There are far to many over priced RVs out there. You need to price to sell not to hang around.
Clean it up, fix the little things and get it ready to go, meaning get your stuff out of it and make it look factory fresh. If there is damage, show it and disclose it. Don't waste your time or theirs. Being upfront and honest usually pays off in the long run.
Take a lot of good photos, the serious buyer will want to see everything to save themselves from showing up and being disappointed.
On CraigsList expand your area, post locally but go beyond the 200 mile radius and post to those areas too. All of my buyers drove over 2 hours to pick up my RVs.
Weed out the scammers; if they don't want to come take a look, just ignore them. I found if they didn't want to talk on the phone they were playing games, same if their number didn't display on my phone. Make it clear its a cash sale or agree to meet at your bank. In my case 1 guy has cash, the other 2 were dealing with financing. I spoke with my bank each time so things would be ready on my end. I had the pleasure of becoming friends with one buyer, been 13 years and we still talk frequently.