I sold tens of thousands of motorized vehicles over a four decade plus career and can give you some basic pointers where amateurs most often make mistakes.
1. Clean it spotlessly and keep it that way until it sells.
2. Make all needed and obvious repairs. Don't assume the buyer will allow in the price to fix it himself. Fix the scratches, dents missing parts. Replace the tires if totally worn out and not just offer an "allowance". Let there be no excuses for the buyer not to buy!
3. Remove all personal items and added decorations that are not affixed. The buyer will not necessarily like what you thought was beautiful!
4. By all means look up NADA low wholesale and low retail values and know what they realistically are.
5. Search continuously on-line for "comparative product" prices even if a competing manufacturer. You are in competition with all of them....not just your model!
6. Call every major RV store in a 300 mile radius and solicit a "buy" offer. Most will give you one, some low and some pretty accurate. This will give you a reality check as to what "range" you are in and keep in mind dealers are normally NOT making ten thousand dollars re-selling what they buy from the public.
7. Prepare to put up with a lot of B.S from the tire-kicking public and various scam artists. It can be a challenge but you can win.
Good luck!