No state income tax leaves you with Wyoming.Washington.Texas.South Dakota.Nevada.Florida.Alaska.subtract SD and AK for snow/freezing tempsSubtract Florida for hurricanes and high insuranceSubtract Texas for high property taxes and some areas with bad foundations/soil conditionsyou could say that also leaves Washington and Wyoming but I’m subtracting them for weather and other personal reasons. 

If you were to get a 5 year option contract, and a 5 year lease, you can have 5 years of cash flow just like you would if you owned the property, but there are no mortgage payments subtracting from the cash flow.Take a property selling for $100k:1- If you buy it you have to come up with a 20% DP (at least) = $20k...if you buy an option, you only need 5% = $5k. 

Subtract the land value = $221k and divide by 27.5   ($8036/yr) for a residential house or plex up to 4 units.

If you were to sell you would subtract 6% for sales costs. 

After that and four months of work, I should have a minimum of about $8-10,000 saved up in addition to my down payment to the loan, including subtracting 1/3 of approximate income for taxes and $500 a month for expenses.  

You take purchase price and subtract land value, which can be a lot in California.

Looking at the amount of work that was needed calculating the cost totaling up total cost and subtracting that from the ARV What was the outcome?

If you don't have financials, you can calculate the expected NOI by multiplying the number of occupied spaces currently paying rent by the monthly lot rent, then multiply by 12 months, subtract the expenses, which can range from 30-50% depending on variables, so use 40% for your back of the napkin analysis.

Even after subtracting mortgage interest, property taxes and insurance, I am still making a profit at the end of the year. 

If the terms were payment over X-yrs +/- down payment +/- interest you’d determine the monthly payment and then subtract that from market rent and that would be the payment she’d give you each month.