If you are mathematical and want to get real detailed with it, learn how to write a discounted cashflow model in excel. 

For example, on the after repair value section of the calculator and the estimated repair costs, how do I find out what the typical costs are for a particular market (I know they vary from place to place from what I've been reading)?

https://www.roofstock.com/investment-property-details/kansascity-missouri/14920-fuller-ave-grandview-64030/1697409 There are a few things I have concern about turnkey properties: 1.

We estimated the value of the home based on similar sales so that estimate minus what we paid is where this amount comes from. - When did you purchase the home?

I spoke to the Brother of the wife ("B"), and discussed the possible situations- Unfortunately after working on the property details and researching the title for the property, I found out that the title belongs to both of them.

@Andrew Postell, thanks for the time and detailed response.

PM for details.  

This sounds way too detailed to be merely hypothetical.But anyhows, to answer the question, I'd have to say BOTH.

I'm planning to turn at least one of the 1/1's into a vacation rental which should earn at least 1200/mo (very conservative estimate, probably higher).Purchase price: 295,000Down payment: 25%, $73,750Loan term: 30 yearsInterest rate: 5.375%P&I: $1238.94/moClosing costs: $2800Gross scheduled income: currently $2650/mo, I'm planning on $3000/mo minimum with STR, so $36,000/yearLess Vacancy/Repairs: 10% = $3600*Gross Operating Income: $32,400Less taxes ($4700 (high estimate)), Insurance ($900), and Water/Sewer ($1800):  $7400Net Operating Income: $25,000Less Debt Service: $14,867Before Tax Cash Flow: $10,133CAP rate: 8.47%COC: 13.24%*yes, I know that's low for Vacancy/Repairs/CapEx, thats because we do our own work and management.  

Do you have a more detailed investing criteria?