I’m not an expert here as I’m currently converting in Europe but have bought and converted in a van in North America. It depends on a number of factors, but at that price there are gems out there however there will be a lot of duds on the market also. Once you’re pushing towards 200k you’re risking having issues and would definitely recommend getting a mechanic friend to look it over if the mileage is on the high side (tbh I’d get them to look it over regardless if possible), always worth having an expert eye involved if you can especially at that price range.
Id check out this thread from a week or so ago where a similar sort of thing was discussed, might be able to get some answers you need from there, if not I’m sure someone will chime in here with more info than I have: