Your total ownership period is six years (2012-2017).

That is totally AWESOME!!!

If you go by the estimate CoC, you are getting 9%, and a total return over a 10 year period you are at 20%+, which for a lot of folks is pretty good. 

Eventually after 5 years or so I will rent both units out with the main unit bringing in 1800 currently in rent to total 2450. 

Thanks for your response @Dave Foster.That is a really good point that i totally spaced with this idea.

I would get 3 estimates for total repair and make sure the smoke damage is taken care of also.

@Elaine Lai As others have said, your down payment/equity is much lower than almost all banks will require (generally require 20-25% of total costs (land, hard & soft construction costs). 

I feel as though we miscalculated something.One unit yields $400 in rent (1 bedroom) and the other yields $800 (3 bedroom).Total Rent: $1,200Duplex Price: $67,000Down Payment: $3,350Repair Estimate: $2,000Closing Cost Estimate: $1,500Total Investment = $6,850We factored in:Mortgage: $340Mortgage insurance (we would have a low down payment): $40Home owners insurance: $67Property tax: $113Vacancy savings: $60CapEx: $60Repairs: $60Lawn/Snow: $120There are no HOA dues.Total costs: $860So, our monthly cash flow should be $340.Annual cash flow $4,080Total Investment $6,850ROI: 59.5%I feel like this return is far too high.Is there something obvious we're missing?

Total cash in hand is 190-195k or almost exactly 20%.

Also, I see the total purchase cost add $3,700 instead of subtracting that amount.