I would say condition, condition, floor plan, quality, cost, proximity, ...
By far condition is the most important factor, if the paint is peeling, roof leaking, wood rotted, tires worn out, the floor plan and price don't matter.
In buying my current coach the first one I looked at 3 miles from home was a fixer upper (money pit) 1996 Safari Trek 2830, the seller was moving out of the US so was motivated to sell, asking price was $6,900. I said it was a money pit, leaks, nothing worked (generator, roof air conditioner, dash aircondition, refrigerator all broken), tires were old, paint peeling. He was down to $4,500 and make an offer when I walked away. 5 months later after much shopping I ended up buying a 2002 Safari Trek 2830 (exact same floor plan as the nearby '96 Trek), it was over 1,000 miles away and I paid a bit over $20,000 for it, however it was in very good shape, well updated with $10,000 in parts alone added in the last 2 years before I bought it (new fridge, tires, carpet, seating, suspension work, solar panels, inverter, ...)