I agree with everything DrewE said. Excellent info.
We bought a 4 year old small motorhome 8 years ago. We had no major expense in the first 4 years, when we needed new tires. There was a difficult little plumbing problem, a broken drain pipe elbow in a difficult place. Could have cost hundreds of dollars but I enjoyed finding and fixing it myself so it only cost $5. You sound like a guy who would be interested in learning how an RV works and doing most of the maintenance yourself; if so you will most likely have few expenses.
We bought an RV that we could afford without debt or compromising other plans, such as moving up if we found it necessary. I think it is a good plan in these uncertain times. We lucked out and are still very happy with our small MH.