Lots of good advice thus far, hire an inspector as stated but definitely talk to them as much as possible. As mentioned you can tell when asking questions, if they responded hurriedly or sounded annoyed we immediately moved on. We always told them upfront we were hiring an inspector, some took it well others not so much. We just spent a couple of years looking for our current Class A going through the very same situation you are currently experiencing.
We live in NM and easily exhausted our search in state, luckily we have TX and AZ as neighbors, both have an enormous selection of used RVs to peruse through, ideally looking to purchase from private seller than dealer. After talking to a particular seller for a couple of weeks and RV techs/inspectors in the area we set out for southern TX. Inspection prices started at $800 for house side, chassis and powertrain add another $400, pricey for sure but well worth it to avoid serious issues.
Our patience paid off, sellers turned out to be true to their word, in fact we stayed in the motorhome for three nights on their ranch. I was able to go through everything myself and drove it around several times, noticed alternator was not putting out sufficient voltage. Pandemic was roaring in TX last July with repair shops booked weeks out, they overnighted alternator and had mobile mechanic install next day. Ended up not having inspection, drove it 800 miles home through record TX heat.