It's the relative difference that matters and how that relative difference compares to the market as a whole with the reval.  

@Jennifer Williams compare the sq ft of the home with the tax record.

@Todd Hays Realize what utilities the landlord is responsible for each month and what each tenant is responsible for monthly as well.Would also check out neighboring apartments and see what the condition of this one compared to the others are along with comparing the rental rates.

Also housing appreciation on the north side is slowing down compared to out west and out south in chicago.

There might be a 30 or 60 day notice clause that requires you to let them know in advance if you're moving.The offer will depend on the rental income and how comparable properties sell in the area.

The product can be a bit more appealing compared to FHA since there is no mortgage insurance involved.

That's not what i've seen based on cashflows from a turnkey provider there whom i've compared to other markets across the US.  

It allows you to compare which are more favorable.On your second point, some turn key property providers are excellent, but they are not all the same.

As a financeable asset, it is evaluated like residential: it is appraised by comparable sales.

That's when you need to compare income to expenses and money cost and figure out the cap rate, etc.