You will want to dig into why they are below market -- lazy seller, poor unit condition, high supply of units, etc.

do new buyers have to sign off on properties not yet brought up to public health standards for Drinking water?

I used comparables through similar sites to what you mentioned and made a list of notes next to them like "similar condition to ours" "small bedrooms" "has a pool" or whatever else was like/unlike our units and then picked in the higher percentile of rents because I knew we would provide more benefits than other units.

In a few words, he is a 50-something single man with what looks like a somewhat unstable mental condition (bipolar maybe?

Given that commercial real estate fundamentals tend to lag general economic conditions, the sublease level is expected to rise into 2021 as occupiers re-assess their requirements.• A significant increase in space availability stands to place downward pressure on average asking rents in the months ahead, but a strong employment recovery will counteract this trend later into 2021.• Post-pandemic, tenants are expected to maintain an emphasis on both work flexibility and wellness for employees, including modified in-office work schedules, continued work-from-home arrangements and access to greenspace and outdoor workspaces.

The house was in decent condition but needed some help.

Also since this is a health and safety issue, you might call your local Code Enforcement Dept for help.

Generally if your credit is good and you have enough income to cover your total nut under 43% the only things you need are: the money, property that is in habitable condition that cash flows.

Not sure of the condition of the roof.  

Other than that, as long as their unit is in good condition, I would say return the funds.