Whoever was supplying it. 

You may want to check out a few mobile home supply stores in your area.

, is that done by the latest appraisal, or is that just owner supplied information that always needs to be verified?

Local zoning and land use regulations will determine that....start with the building and zoning dept, or whatever it is called there.

be careful to check to local regulations, for example; in Connecticut where I am you are not allowed to refuse occupancy to potential tenant based on section 8 usage.

Your statements about price, supply, and days on market are very much in line for what I am seeing for "affordable" single family homes in B class or higher suburbs (about $250k or less).   

I won't go into all of them, but the primary thing was that our kitchen cabinets were basically falling off the wall, the dishwasher stopped working after using it 3 times and the P-trap under the sink was malfunctioning, causing a constant water drip and massive hole under the sink - which they had covered up with a shelf and cleaning supplies.

You are correct it is a supply and demand issue.

I'm thinking about either a two-building situation and renting out one full time or possibly building a glamping style place on a plot, but I think the regulations make that more difficult now

@Idan Narotzki it really depends on your state regulations.