Fellow old RV buyer here. We bought our 1990 Winnebago Warrior about 5 years ago. It was 19 years old when we bought it. It is now 24 years old. How time flies. We paid $7500 for ours. We have 2 kids, 5 and 8.
First thing is,
trust your nose. If it smells musty, moldy, or mildewy inside, or if it smells like someone has bombed the place with Fabreeze or Lysol, be very wary!
Our RV had a leak in the sun roof in the shower, and this turns out to be a typical problem - I once ran into our camper's "twin", one model year older, with the exact same problem. I ripped out the shower and rebuilt it but we still have a mold problem and my allergies go ballistic every time we use the RV unless I take an Allegra every day and then I'm fine.
If you already know you've got a leak problem, I would be very thorough in prodding things feeling for soft spots, and pull back carpet or upholstery or whatever is possible to look for rot or signs of water. I'd get an estimate for repair and use that as negotiation for coming to a price.
Insist on the seller showing you the operation of every single functional component on the vehicle. Refrigerator on gas, 12VDC, 120VDC. Stove. Oven. Microwave. Vent fans. Water pump. Generator. Engine. Cab AC. Roof AC. Cab heat. Furnace. All faucets. Toilet. Drain valves. Dump valves. Leveling jacks (if it has them). TV. Everything.
Make sure that the generator runs for at least 20 minutes without problem. Our generator started up and ran fine but turns out it would not run for more than 20 minutes without shutting down. That cost us $500.
Make sure that the internal water pump runs and shuts itself down when it pressurizes the system and that it does not come back on again for the duration of the time you are looking over the RV. If it turns on again it indicates the system has a leak and is not holding the pressure.
Everything that cannot be shown to be operational should be assumed to be non-operational and you should negotiate the price based on that.
Tires have a 6-year life. After that you are on borrowed time. A blow-out can rip the guts out of your RV damaging many internal systems costing thousands to repair. 5 years ago we spent about $1100 for 7 new Cooper tires.
To summarize, here's what we bit off:
$7500 for the RV.
$800 to repair cab AC and convert to R134A.
$500 fix generator
$1100 new tires
$500 rip out and replace shower and recover portions of ceiling.
total repairs: $2900
Would we have been better off spending $11000 on a nicer RV? Maybe so. But at the time of purchase, we didn't
have $11000. So, we live and learn.
It's been a nice RV. It's been to Disney and back 4 times. My wife is there this week with the kids and her Girl Scout troop.
Steve
1990 Winnebago Warrior. "She may not look like much but she's got it where it counts!"