New to Buying a Used Class A - Have Questions.

I took my 2002 Ford V10 in for new spark plugs, cost est. was $300, service mgr. said the V10's do not brake off, but the V8's can be a problem. They have to work V8 plugs back and forth with 30 lbs. of torque to remove then. The cost for the V8 was $500.

The F-53 Chassis is the one that had the spark plug issues, it seems there were not enough threads in the head and the spark plug only had like 2 or 3 threads to hold.
The no dash air is a very common problem with the F-53 chassis too, on mine the metering device was bad, not a hard fix but you have to open the system to replace it, that means pulling a deep vacuum before adding Freon. Most of the folks I know choose to run the generator and the AC unit on the roof instead of the dash air. Better cooling, more even, and cools the entire coach instead of just the drivers area.
Another common problem with the F-53 chassis is they ride like a truck. At least mine did. Even after new shocks, new tires, etc it was still a dog rough ride.
As far as dependability though, the V-10 is hard to beat. But that goes for a lot of other engines too. You will wear out the coach long before you ever wear out an engine.
Just my .02 worth.
Good Luck

Ford V-10 has issues with spark plugs breaking off when trying to be replaced. Best to have current owner do tune-up including spark plugs.
Appliances are always issues on some rigs. make sure they all work.
Dash air is an issue but isn't that costly normally to fix. Have current owner get it done by a shop.

The a/c is a big issue. If just freon no to bad, but if compressor then big dollars. That would be something they need to fix. Tires are tires and have to be replace as needed. I have a 99 Newmar on a ford and have had no issue with it but that one is a newer engine.