As a rental with $200 positive cash flow, the tenant will be paying the equity paydown.I am going to assume your $200/cash flow projection is accurate and that you properly accounted for vacancy, maintenance/cap ex, PITI (Principle, Interest, Taxes, Insurance), Property Management, and miscellaneous costs.If the unit performs for the next 4 years similar to the last 4 years, not including compounding or rent growth, this is what the return would be:$40K + $200 * 4 * 12 = 49,600 or an average of just over $1k/month. 

. - some sort of parking / storage compound?

Your rents are compounded with more renters so that is an instant increase in cash flow.

@Mary M.  ...or, you just analyze properly, buy correctly, and live off the CF while you move your cash through the rental properties by selling them as they gain equity to get compounded returns.First, profit isn't made on the spread between the interest you pay and the cash flow. 

I've been in them for other industries and it's like compound learning - very powerful and great for meeting people who are serious. 

Flipping is a much faster way to compound your cash and scale into larger properties for long term holds if that’s a strategy you would like to implement. 

If each property appreciates at 5%, then the new PV for the first option (leaving it as is) would be $126k, but the new PV for the 2nd option would now be worth $210k...and the gap increases as time passes because of the compounding effect.It gets better, or worse...depending on which side you're on. 

That compounding % you can save over the course of a loan is free $$$$$.

It has appreciated far greater than 4% annual rate and probably over the 8% that I was expecting (I have not calculated the compounded appreciation).  

You can even do it multiple times to compound that!