One option is to have the buyer use a loan to buy out your existing mortgage, and then you can carry a second lien on the property for the remaining balance.

Given that the house is paid off but has $27K in back taxes, you could offer to cover those taxes upfront in exchange for favorable terms on the remaining balance—like low (or no) down payment, and small monthly payments.You could also negotiate for a subject-to deal where you take over the property subject to the taxes, while still securing control of the property for your BRRRR strategy.

By your own admission you don’t have the balance sheet to buy real estate or borrow and haven’t taken any projects full cycle.

The land is often far from urban areas where housing is needed most, and environmental concerns must be balanced.

IF, they were willing to take the risk inherent in all “subject to” transaction done without lender approval, they would have also been able to “capture”, and added to their wealth, the difference between 9% and 3.25% on the underlying $375,000 loan balance, or about $21,500 per year.3.

That's the tough part...we really like them and want them to stay, but we got creamed on taxes this year, so we do need to charge more to make it balance.

If your purchase loan is $100,000 and you have $25,000 in rehab holdback, you are only paying interest on the amount of the principal balance each month. 

I hung on the cubicle for balance with my head down and kept muttering to myself, no door, no door.

Check, Zelle, PayPal etc.Then require balance 30 days before stay.

Typically 5+ units is ‘commercial’ or ‘small  balance’ multi family.