From that subtract your mortgage (at 20% downpayment your looking at financing about $117k which comes out to just under $600 a month for principal and interest on a 30 year 4.5% loan ).

Subtractions to that include tax and insurance at $2,000, vacancies calculated at 5% of rents, Maintenance estimated at $1,000, capital reserves estimated at $1,000, and management estimated at $2,226. ( I usually have to pay 10% of rent + one month's rent to find new tenant.)If I have done my math right I get $7,066 for expenses and net operating income of $9,734. 

Subtracting the expenses from the rent gives me $14,476 in NOI. 

You can maybe use county records to see what the assessors report has for the tax value of the property, but keep in mind it may not be absolutely in line with the current demand.So essentially, what you need to know when analyzing each deal is what the home can realistically sell for in your area based upon similar, recent sales and then you subtract from that what it is going to cost you to actually purchase the property up front and what it is going to take to rehab it and then further more subtract the total costs of ownership (utilities, insurance, loan, etc) for the period of how long it will take to sell the house - and obviously that can be tricky. 

Then subtract value from the properties that have extra beds, baths and features to bring inline with subject property.

@Toshia Booker-BlakeleyWe prefer using 65% of the price instead of 70%  Then subtract repair estimate, holding cost, closing cost, and if you plan to wholesale it subtract your assignment fee.

They will let you down.Simple formula for success:Negotiate properties 65% or less of current market value and subtract repairs to market condition. 

Subtract off the profit you want and that's the top price you need to negotiate. 

Bill SchrimpfA couple of points that you are overlooking that should work in your favor-- taxes should be included in the 50% of expenses, so when you're subtracting out the mortgage payment, just count the P&I.-- the HOA should be covering exterior maintenance and maybe some utilities (i.e. water for my condo) which should cut down on how much you need to budget for those.

That's what's left after subtracting all expenses.