So, you would take your gross sale price and subtract your routine selling expenses (broker's commission, title/escrow fees, closing attorney fees, recording fees, exchange fees, etc.). 

From that amount subtract all of the expenses.

Assume you sleep 8, 2 for hygiene and bodily actions, a regular 8 hour job, leaves you with a total of 6 hours of "free" time; which then you must subtract every other part of your day; commuting, grocery shopping, laundry, etc.Now if you can use those 6 hours to make money that you would otherwise save, it make sense.Here is some good info from somewhere else (in 2013):"It's Literally Not Worth His Time to Pick Up a Dropped $100 Bill From the Ground.

you'll also want to leave a buffer for concessions since most buyers ask for those when you go to sell the property, and also a buffer in case the rehab goes over budget...as you can see, these "reality shows" that subtract sales price from purchase and rehab price are not accurate at all!

Subtract your basis.

Subtract the interest expense from the MAO to get the net MAO ($56,110-10,800=$45,310).Again the net MAO is the max I'm willing to pay for the house; that being the case I can't pay the MAO.

You can take the actual number of spaces in the park and multiply this by the actual rents being charged and subtract out a reasonable allowance for collections and you should be able to come up with a good estimate of the income.

You would then subtract out the land value and depreciate the rest over 27.5 years.If @Steven Hamilton jumps in, he will have the correct answer.

Then subtract pension and social security.

When you sell, the gain on the sale is the sales price, less selling costs and then you subtract your basis.