Never buy new Rv's and boats!! Depreciation is not your friend and these items lose half their value in two to four years. I have bought two used 5th wheels, a 24' and then a 31', and both caused me no problems to speak of. Both were two years old when I purchased them. This latest 5th wheel I had tried to purchase new and the dealer would not budge from $38k and I found an exact model two years old at $21k.
There are a few things you need to look for in purchasing a used RV of any type. Check for leakage around any seal, moulding, roof or window. There usually is some visable sign of leakage such as stained plywood under dinette cushions, dark spots on the ceiling or vinyl floor or discolored paneling. Leakage is usually the thing that eventually kills an RV' value and structural integretity. They will ... ALL... eventually leak somewhere so constant maintenance each Fall or Spring is mandatory. Caulk dries out and the constant movement of the coach walls give way to water intrusion somewhere. It is not such a problem to scare you away from RV ownership but it is something to be aware of and stay ahead of. Anytime you can see a hairline crack in a caulked seam this need immediate attention. Pull the old out and put in new. You will become good at it. Our 2006 looks as good today and the day we bought it and this is attributed to good maintenance. Plus I still have the other $17k in the bank!!