I've bought and sold thru Craig's list and haven't had any problems. However, I asked for and received a bunch of extra photos before traveling to another state to look and eventually buy a coach. I knew what to look for and accepted the premise that the seller wasn't going to tell me everything. He didn't, but that wasn't a problem. I fixed the minor problems (that he didn't have the ability or knowledge to do) and we're happy.
The most serious thing to watch for is roof leakage or any water damage. The other potential serious problem can be the drive train; engine and transmission, which can be expensive to replace. Brakes, suspension components, tires, etc. are all reasonably inexpensive to replace. The house components are supplied to the manufacturers by others and are normally reasonably easy to replace.
