On craigs list, alternative if you are looking for a sprinter but can't afford a fully built one.
https://sandiego.craigslist.org/nsd/cto/d/oceanside-2016-ram-promaster-campervan/6900339034.html
https://sandiego.craigslist.org/nsd/cto/d/oceanside-2016-ram-promaster-campervan/6900339034.html