An older, well built, high initial quality coach is in your price range, something like a Monaco, Beaver or Safari built around the turn of the century. However, as an owner of a 96 Safari, I can tell you that things will break and you'll need to be handy (or have the phone number of the local mobile RV repair shop on speed dial).
We see it here all the time; people buy a low cost coach and they're here complaining about quality. Don't think you'll escape issues if you buy new.
I also question if you'll need something as big as 42 foot, especially if it's just you and you'll be mostly in the same place.