Rental comps for 2BR units in the area are $965/mo.Assuming I purchase the property for $135K, invest $10k in improvements, utilize a 25% down/30 yr mortgage, and achieve 80% of the total market rents (from rentometer) + 7% vacancy/attrition, this property looks to cashflow approx $400/mo with a 9% CoC return and 12.5% total ROI.My questions are the following, not having much experience in analyzing duplex deals:- How would I accurately estimate rental income in my area for a duplex, if my area is mainly SFHs ?

Seller shall provide such documents and information, which they believe to be true and accurate, within 5 days of acceptance of contract.

I have no desire to lose money monthly to gamble on appreciation, if I want to gamble I'll buy a lottery ticket.  

@Jerome Hawkins The first step is to try to get an accurate read as to why it's not selling.I think it was Brian Tracy (sales trainer) who said "prescription without diagnosis is malpractice."

I'd say the $2,000 is pretty accurate if you are using the assist.

My goal with the pictures is to present an accurate view of the accomodations.

These are a few things that struck me when I read your post:While it's good to be careful and analytical when running your numbers, the specific details you gave above regarding cap rate, etc. aren't accurate.

@Jason Brattner cap rate is a reasonably accurate way to measure investment opportunities without taking financing into account.

For a completely vacant property, how do you determine an accurate purchase price? 

Check the local banks and credit unions. 25 year amortization is more typical for a loan that size so I would make sure 30 yr am is accurate.