So, we get $30k to $50k option fee to spend plus cash flow.The tenant buyer is responsible for all repairs, cap ex and clogged toilets.

You will get tax write offs if done properly.Move your ex-wife and kids into one side, you in the other, rent out the other rooms either long term or as short term rentals.She made mistakes too, it isn't one sided.

My ROI will only be 17% not including cap ex and vacancies.

That's why selecting a tenant is as important to me as selecting a property to buy.However, to Joe's point, I have never invested the time to learn evictions and I won't do it, but I am happy to pay for the service if I ever have to and get it done professionally.PS: a great book is Mike Butler's Landlording on Autopilot - he's an ex-cop, very street smart.

The other buyer happens to be an ex lawman..

I’m looking for something that can accurately calculate depreciation of both the property and cap ex.  

…but then I think about John, the American hero who spends long hours driving an ambulance to provide for his family and make alimony payments to his ex-wife.

Ex:1.

Is there deferred maintenance or any cap ex you intend on investing into the property?

For some, 200 gross cash flow - Rent minus monthly payment is enough for them for it to be a dealFor others then need to have 600/m in NET cash flow deducting 10% for management, 10% for cap ex, 10% for maintenance, 5% for vacany etc.