My .02 - if you can find a decent, older rig, go for it. My current rig, a 1989 Layton had some minor staining on the interior roof ceiling panels from a prior minor roof leak. I checked the entire rig very well and all walls and floors were still solid and everything worked, it had a replacement water heater and the prior owner installed a newer dometic refridge in it within the past 5 years I'd say. It had obvisoly been sitting for awhile, but since it seems sound, and the price was very reasonable, I went for it.
The Awning is not in the best shape, but still useable, I made a temporary repair on the exposed portion (when rolled) with some eternabond tape which is holding up well. I also ended up having to replace the tires (I should have figured doing this right away anyway, the tires were not dry cracked when I looked at it, but by the time I had gotten the rig home they had cracked, due to sitting. I say this rig probably sat, unused for at least 2-3 years before I bought it. The prior owner obvisouly had taken care of it as the paint on the aluminum siding was still in good shape.
The interior needed a good cleaning, but I enjoy doing that anyway. I wire brushed and re-painted the entire trailer frame, sealed all the exterior side penetrations (windows, doors) and roof penetrations as well with some Di-Cor calk. I also did an over-slung, (relocate axle under the leaf springs) axle conversion on it ( trailer had very minimal ground clearance before)This past year before annual inspection I rebuilt the entire suspension on the trailer, all bushings, equalizers, shackels, etc with "wet" bolts.
I found some things along the way that I didn't see up front, but nothing major or that required immediate repair or that affects using the camper so I'm not worried about those.
Some of the issues I have just chosen to live with, others I addressed. Bottom line for us, for the 4-6 times per year it gets used, it works for us. I do not wish to have a camper payment or pay 10-15K+ on a new camper, which we all know is a horrible investment (money wise, generally RV's depreciate very quickly) which will sit at my house the majority of the year.
If you are one who uses your rig every weekend, every other weekend, snowbirds in it, or whatever, I can certinly see the benifits of buying new.
Another advantage (to me) of the older rigs is they are built with heavier framing/materials becuase back in the 80's weight was not as much of a concern as it is today. Also, my Layton has a one-piece aluminum roof on it, a lot of rigs from this era have aluminum roofs, which I personally really prefer to the newer RV's rubber roofs. My rig is now nearly 26 yrs old and still has the original roof on it. I don't care how well you take care of your rubber roof on a new RV it would be lucky to last half that long.
Again, pros and cons, these are just my opinions. Others may disagree and that's OK. It's all personal preference, what you like and what works for you personally. I spent a lot of time initially cleaning and making repairs to bring things up to my level of maintenance standards, as I do all my equipment, but I now have a rig that need minimal maintenance and that my family really enjoys camping in.
I would caution you on getting an older rig with slide-outs. I'm not a fan of slide-outs, others like them. To me, it's just a big hole cut in the side of the camper that is an extra place it can leak. They do open up the living space a lot, but again, this a camper for us and we go camping to spend time outside, not inside the camper. It's got a nice layout with bunks in the right rear corner for the kids, a slide out couch for my wife and the table folds down for my bed. Your needs/wants may vary. For what we do and how much we go, I don't need to be bothered with slide-outs, leaks or the hydraulic system failing.
My point in all this is that if you find a rig, even if it has some evidence of water leakage, if the roof, walls and floor are still sound, I would not automatically condemn it. It's going to be hard to find one that is perfect in the age and price range you are looking at. Look it over real good or take someone with you who knows RV's and knows what to look for.
Good luck!
2017 Dodge Ram 2500 HD, 4x4, CCSB, 6.4L HEMI, Snow Chief, tow package.,1989 Skyline Layton model 75-2251.