If your average heating bill is $150, you may not collect enough in the winter months when the bill reaches $225 but you'll collect extra in the summer when it drops to $65.

-A water heater issue resulted in repeated mismanagement—confusing unit assignments—leading to extra costs to fix the same issue 3 times and on each occasion "more fixes" needed to the water heaters that I plumber said was needed.

One thing that I would like to add to this list is making an investment without having enough extra money to get through the medium times as well as the bad times.

Before you close, can the rent from your buddy and the midterm tenant cover your mortgage, taxes, insurance, plus a bit extra?

You'll want to have an insurance agent familiar with rentals since a lot of the extras on your coverage that you will want, the average insurance agent won't know to give you. 

If I find the buyer I would charge and extra 1.5%. 

The extra income is not worth the disruption to our neighbors.Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

We have been able to get some great deals simply by doing extra research that the average person wasn't willing to do.

I can definitely enter other markets, it's just gonna take some extra digging and research to find the good ones to work with. 

I’ve consulted several different people and they have told me in my situation as an investor expanding their portfolio it makes more sense to keep the extra cash as opposed to paying down rentals.