The amount on the letter was higher than the sales price of the house. 2 days before closing (within the 25 days of backing out incase of financing not being approved) the buyers agent came back and canceled the contract, and provided a letter from the lender which stated 2 reasons for financing falling apart. 1) Insufficient income for amount of credit requested2) Excessive obligations in relation to incomeThe buyers agent also told my agent that apparently the buyers had purchased a car 3 months before they went in for qualification and the lender didn't find that account in their credit report and thus provided the pre-qual letter. 

It seems like I always lose a full months rent though by the time it all works out.

It is also one of the easiest to lose your shirt if you don't.

We‘re nor sure how to fInance the next property we have about $30k of liquid cash that we’re comfortable spending if need be, but would definitely be more comfortable using OPM and not losing our leverage.

I would look into doing RUBS if it is possible in your area.If you are losing so much in laundry cost you might want to look at raising the cost per load or if possible shut it down completely and save $1400 a month.

Ok.... couldn't buyer be somehow working with the private money person to dupe homeowners into doing this though... thus taking a big chance on losing their property?....

Also, worst case scenario is if you leave secure job, and lose your $80k in BRRRR.

I'm not saying you'll ever lose money but beware of it's riskiness  and it will probably cost you twice as much as you budget for turnovers. 

The downside is you lose the experience of someone else with more or different experience than you, my guys have helped me avoid a lot of major issues through the years that I would have missed. 

I'm sure the interest rate is high and at some point you will begin to lose money.