Rockem, what the owner is paying is irrelevant. Rents are set by the market, not by cost.

What is legitimate is to investigate to what extent the owner could be facing foreclosure. Other than that, knowing how much the owner pays every month is irrelevant for setting rent. Owners charge the highest rent that the market can bear, regradless of cost.

Of course, if the property has negative cash flow, the owner won’t be in business for long.