Our rig is a 2004 model with under 10K miles on the odometer. Illness etc has kept usage and mileage way down. We have had to replace the fridge, roof AC, converter charger, fresh water pump and house batteries and awning. The engine, cooling system, brakes, transmission and dash AC are fine. If I were to sell it, it would be a good buy. Because of non-use, we have changed oil and filter every 6 months or so. Not every unusually low mileage rig is a potential money pot. I would be very careful buying an unususally high mileage rig. Average RV mileage is about 5-6K miles per year. 80's to 90's rigs may have carbureted engines that labor excessively on grades at high altitudes, overheating problems, suspension problems, and appliances that are about to need replacement, water leak damage, and a lot if amatuer electrical and plumbing repairs for the new owner to deal with.