While this figure takes some work to arrive at, there’s nothing illusory about it.

What I find with 6 month leases is that the tenants all stay longer....they wanted the flexibility when they arrived.

. - doesn't jiveshe arrived to see the property in an Uber, a small compact car with her 3 big kids she owns a 2012 Toyota, that's ither furniture didn't look very nice, cheap, and hardly any, she has boxes of junk though.she let me know she was going to do the landscape (pick weeds), - how many people making that much money are out there picking weeds, btw, weeds still there.

Show separately for 2017 and the 3 preceding years: gross sales, cost of goods sold, gross profit, percentage of gross profit to gross sales, amounts collected, and gross profit on amounts collected.It seems, after reading this, that your solution would be the correct one - enter the gross profit for each year on Line 1 of Schedule C with a separate statement attached to the return describing the installment sale and how you arrived at the gross profit. 

Another related question: Where do owners go when guests arrive? 

They shouldn't necessarily dread your arrival

Many of the medical professionals line up housing in advance, some 30 to 90 days out, and I want to require a deposit to hold the property until they arrive to sign the lease and move in as I am getting multiple calls for the same time frames.  

Besides looking in other markets, which I am doing, look at ways to add value so that you cash flow (20% down, great deals, sub-meter units, petition tax assessments renovate, rent increase) and then make sure you have equity in your property when you sell to get paid on the backside of your deal. 

Are you trying to arrive at a value to sell the portfolio or just to inform the owner?

They normally arrive in the middle of the night, so I meet up with them the next day at the house.