You need to calculate it as investment income - expenses (including annual taxes and income taxes on your gains) - increased equity (loan paydown - that is part of your profit, but it isn't part of your cashflow)If you are looking at this on only a monthly basis, you'll miss annual or semi-annual costs or seasonal variations. 

So that is another area where an experienced person would be a huge benefit. 

It's also important if you are on a 1031 exchange as well using those proceeds to buy their property.They could still 1031 exchange possibly you just do not want it as a contingency in the purchase and sale agreement.See if they would owner finance as they might not want to buy anything else but also do not want to get hit at once with capital gains and depreciation recapture.   

.* And of course one of the biggest benefits for the owner/investor is that when doing the lease option, the tenant will be responsible for all utilities and maintenance.

But anyone who bought anything a few years ago should be rolling in gains. 

If you quality you will enjoy the benefits such as large contribution limits up to $61,000 per year, exempt from UBIT tax on leveraged real estate, ability to invest tax-free using Roth sub-account and more.

I have a full time job and I'm considering Real Estate Appraising to both gain skills and earn some extra income to jump start my buy and hold RE investment strategy.

@David Weintraub thank you for responding.Until a person builds a network of trusted lenders, we end up having to knock on doors and present our Property, it's Benefits and our Exit Strategy....

I'm planning to use the contract that I've gained from a friend who has 40+ properties2. 1 house is rented and one vacant3.

It could be worth a shot and my folly could be your gain :)