I have stayed at "conventional" B&B's that I've noticed apparently also list on AirBnB and they've been fine. I think a general point whether we're talking renting a room/apartment, ordering online FBA, etc. is that a lot of people bargain hunt. While that often works out, there's also a reason for the saying that if something looks too good to be true, there's a good chance you're going to get burned.