>>1155221I'll try and touch on prices too.
Generally it seems for a DIY low end live in project you're going to want around 2k to start out. That's mostly to buy the vehicle/trailer and get it road ready. You can do insanely cheap builds depending on how minimalist you want to go. Private sale used van is probably the cheapest you can find. Used vans from dealerships may offer maintenance records, but dealerships are ALWAYS overpriced. Many times the vans you see there are bought from city/county auction and they're just trying to flip them. You can really afford to be picky with your van, there are so many options out there. With 2k you will have access to probably 80% of used vans.
Used school bus tends to start around the 2.5-3k range. Used transit bus starts around 3k. I'd have 5 put back to buy a bus, anything you end up needing to fix (non DIY) will be way more expensive here. That said I have a smidge over 3k into mine after buying a brand new engine. The deals are out there, it's always worth looking hard to find what you want.
Trailers are stupidly expensive. If you're wanting to DIY a flatbed or a toy hauler trailer you'll be spending just as much on the trailer as you would be buying a van or even a cheap bus. To DIY a flatbed you'll have to build to codes and all the lumber and metal will end up being expensive. Re-doing a toy hauler/standard black trailer you see everywhere is way more cost efficient. Just buy the trailer and you're set. Nothing mechanical to fix, long as there's no leaks you can just start building.