Thanks for this question.
While on my search, I wondered about this too. As a n00b, I know only that I know very little. So I took an unconventional approach. Having an inspector really helped me.
I'd looked at a couple of used A/S in the past and was unable to make a decision. A WBCCI
member hooked me up with an original A/S owner who was selling their 2004. I tried without success to locate a volunteer A/S inspector. So this is what I did:
-downloaded the inspection checklist from this site and reviewed it several times, & made copies of it
-enlisted a friend who is a home inspector to do a modified inspection--no written report except the checklist, notes and pics
-asked lots of questions of the owner and had him demonstrate operations (sometimes more than once!)
-took a lot of pictures and notes
-examined and briefly operated every appliance, looked in every cabinet, operated every light
The inspector used the checklist, moisture meter, voltmeter, inspection camera, receptacle tester, and other tools of the trade. It checked out well. Owner's patience started wearing thin after about 4 hours
so my crew took a break and went off-site to compare notes and discuss our "findings". Having no prior TT experience, my inspector would neither suggest or discourage the purchase. I evaluated all the information on my own. Hearing from someone who was not emotionally involved in the purchase was great.
I was pretty sure at that point so asked to spend a night in the A/S. By then we'd established a rapport with the owner. They said yes and we set a date.
A week or so later, four of us (inspector, me, and our SO's) slept over parked in the owner's driveway
-practiced using the furnace, water pump, hot water heater, oven, microwave, a/c, shower, heat pump, awning, stabilizers, shore power, battery power etc. (though not all at once!)
-examined the power panel, the converter, the plumbing under both sinks, the electric hitch, sewer and gray water set up
-crawled under the A/S and took pictures of the underbelly
-AND we baked a pie in the oven to share with our hosts.
We all shared coffee and pie. After the inspector and overnight guest left, I was ready to discuss price with some assurance. I had the checklist and notes in a folder. The negotiation was fairly easy as there was little to disparage that hadn't already been noted, and little to brag about that hadn't already been emphasized.
They gave me the service records, all literature related to appliances, many of the little extras like fuses, hoses, tape, and most thrilling of all, the blue airstream folding chairs! When we shook hands over the deal I was in heaven. And still am. Not a moment of buyer's remorse or disappointment. Only the wish to hit the road more often.
Two weeks later, we took an amazing shakedown trip with no mishaps. This summer, we attended several rallies and took a few trips on our own. I also took a six-day solo trip which was exhilarating.
If I ever get to do something like this again, I'll find an inspector to accompany me. It's really good to get an opinion from someone who is outside the equation. When I get more experience, I'll volunteer to inspect. In the meantime, I would recommend having someone with you to act as an inspector. Having an inspector was a tremendous factor in my confidence in the purchase of my "Beauty".
Although this method is not for everybody, it sure worked for this n00b!