I use NADA guides. I have been looking for an upgrade coach and I have a 2004 little motorhome that is in very good if not excellent shape. I have been watching the prices on NADA for the last couple years through Covid and the numbers fluctuate a lot, but I think at any given time, they reflect the current market prices pretty accurately. Private sellers who bought during covid still want the moon for their coaches as they are trying to cash in on making a profit on a product that depreciates every year. Fortunate for me, I still have a good little coach that runs like a dream. So I continue to use her and perhaps one of these days, I will find the coach I want. When I do I will ask a reasonable price for mine.
Dale