When we were looking at motorhomes, I really wanted to buy used because I knew how much new motorhomes depreciate.  We looked for 3 years and didn't find a floorplan (on the used market) that we both liked.  Finally found a floorplan that we both loved but it was on a new motorhome.  I figured if we purchased out last motorhome first, that I wouldn't care so much about the depreciation since I knew we would keep the motorhome a long time.  Boats and RVs are definitely not investments so I tend not to worry about the depreciation since I knew going in what would happen.
If gas prices keep going up I am sure prices on all RVs will come down. 
Burch