A mint condition Uptown duplex may be well north of 10 and a property that may not qualify for FHA (due to condition) may be 5 to 6. 

All said, there can be numerous reasons a property is listed for an extended amount of time that have nothing to do with the physical condition of the improvements.

Document condition of every unit at time of purchase.

Assuming it's your own house,  I'd look for the big ticket items and the condition-- how old is the roof/HVAC/electrical/plumbing, as those will be your most costly repairs.   

Ductwork within a conditions space should not sweat that much unless its super humid. 

It is only a matter of time before the resident default to previous parking habits so I would recommend putting in lines as the long term solution because drivers are conditioned to park inside painted lines.

Well I guess that more so would depend on a few different factors such as the condition of the house, rehab costs, the relocation costs, new comps of new neighborhood, any permits that have to be acquired and probably several other factors I'm unaware of. 

With a background in digital marketing, branding, and technology I am currently serving the a co-founder & COO to an event based social platform.

You might also get familiar with insurance rates, property tax rates, and FHA guidelines for condition if you plan to use that type of financing.

Let's keep that track record in mind, and not forget that Ben Carson works for a real estate mogul president, before concluding that everything is secret socialism being snuck in the back door.