Actually, buying a used MH is almost exactly the same as buying a used car.
Its hard to make an offer on something based on photos and a description. When we bought our first MH, It was in Albuquerque NM, I was in Ohio.
I had the owner send me a copy of the title and about 100 photos of everything I could think of.
I sent him a PayPal for $100 non-refundable to hold the vehicle for me for 1 week so I could get an airline ticket.
If I decided to not show up or call off the deal, the $100 was his. He was welcome to let other people look and drive the MH but I had first rights.
If I showed up and the MH wasn't as shown in the photos or title, I could call off the deal and he had to give me my money back.
There is still a lot of trust in this kind of transaction. On a high price MH I would use an Escrow service.
We use these when we buy airplanes. Everything is deposited in escrow, when all the conditions of escrow are met, they release the title and funds.
Good Sam had a little writeup, but I'm getting error when I try to goto that page.. Make sure you use a reputable firm, do NOT send ANYONE any money, you will lose it.
Look at this one - Escrow services for RVs