If that number is greater than the purchase price of the house, then I would consider buying the property after looking at other factors (location, condition, neighborhood, zoning, etc).In other words, 6 straight months of rent should pay for the house. 

that's the issue with older properties in the midwest.and the weather is not as good =) but you know that. 

I am under contract to buyOffer was made with inspection contingency Seller agreed to repair or replace furnace a week agoI asked my realtor to check on the progress of seller and they have no real news for me a week later, other than an HVAC guy was on property- per sellers realtorMy loan is conditionally approved pending appraisalI told my realtor I’m not ordering the appraisal until I am satisfied with the progress being made to fix/ replace furnacIs that unreasonable?

Weather that's for swapping numbers to meeting in person for coffee.

I'm personally focused on commercial real estate, particularly affordable housing development as market conditions are good for that.

Not aware of a reliable source for this info - and please don't think US Census Bureau is the answer.3) How do you account for "property condition"?

All depends on the area and goals.In a B-A class where rents are under market and condition is not great, I would prefer vacant, renovate, and rent outlate payments, under renovated, etc are to be expected in C-D class.

I would keep her on a couple of conditions. 1.

Account for costs associated with capital expenditures such as the condition of the roof, foundation, and HVAC.

The way I see it, you rented the house in as-is condition, which contains wiring that isn't code now but was code when it was built and a property owner has no obligation, if the law doesn't require it, to upgrade homes to meet new building codes.