If a person was already in the business of renting out a piece of property, this might be a good deal. However, the idea of letting someone you find over the internet into your guest bedroom is not at all appealing.
I suspect the shared room is for 2 people, hence the higher cost. It does have B & B in the name so I'm assuming it's based on the British system of B & Bs, which charges for for 2 people in the room than one.
Not that I would really want to do that in the first place. Plus, I got an insultingly low rate (read that as: they obviously know what my hovel looks likes).
Well, their x-ray vision must not be working here. My official town is a hugely gerrymandered place that encompasses the Oaxaca airport. Thus, it would probably show up as a desirable locale on their little calculator. I could go ahead and rent out the room, then video the looks on the faces of my bamboozled clients as they disembark at my house in the middle of nowhere, after their toil up the rutted dirt road.