To figure out how much you saved you would calculated your taxes owed at $60k and then calculate your tax owed on $54k and subtract it from the first number. 

Take that and subtract materials, training, insurance, and other fees.

For example can I subtract closing costs out of my gain?

In calculating your cash flow I see 1250-400-70-477(the mortgage on the 84k you're going to refi)=377/mo (and this doesn't include subtracting for the expenses I asked about). 

You didn’t add or subtract to the homeless count.

Just about any lender will recalc your profitability by taking 75% of your rent (NOT your profit/loss) then subtracting your expenses. 

Then subtract expected income tax rate.

Someone that makes 3x the rent, and meets all criterias is likely going to keep there job, or atleast be able to weather their own storm.I think tenants that make 3 X to qualify for a 700 dollar renter will not have reserves.. tahts 2100 a month before tax's subtract 700 for rent  150 for utls.. etc that leaves them maybe 1k a month to buy food cloths insurance car if they have it etc..

Even worse during the 2008 crash with property values dropping, many people were underwater, so the property subtracted from net worth.

Now if you say525k (subtract) transaction costs to purchase (subtract) transaction costs to sell (subtract) interest, condo fees, taxes, insurance, utilities during the period you lived in it (subtract) any maintenance and other fees the rent hasn't covered during the years it has been rented.