So I have gone thru 2 campers, one was free and the other was like $300 over the years and I am simply done with old POS crap that falls apart after about 3-4 years of use.
I also want a camper with a damn bathroom. So I am looking at wanting to spend $3-4k for one and I believe most with bathrooms are like 8.5' and longer.
But what should I be looking for in that price range? I don't want a POS but don't want a $25k unit either.
Look for dry rot. Soggy floors, open cabinets, feel the back walls, and inside roofs of the top cabinets. Walk on roof of unit, feel for 'soft' spots. Look under everything, looking for any indication of rot.
IF you can find a 'solid' camper in the under $5000 range, then look at basics next. Enough space in the shitter, so you can sit down without your knees hitting the wall, while wearing boots. Enough headroom on the main bunk, so you can get out of bed without hitting the ceiling. Check the 'roofing' material. One piece fiberglass, plastic, or aluminum is better than a 'rubberized' membrane roof. And multi-piece aluminum with seam sealer is also a turn off.
Then look at secondary amenities. Such as stoves, furnaces, water heaters, camper jacks, fridge, etc.
In this price range, you'll likely be looking at something pushing 20 years old. And you're likely to have to be very selective in your search.
If you step up the price range, look for something under 10 years old, but under 10K, and will probably have a 'keeper'
My 2 cents.