Share your insights or perspective on the financial matter presented in the input.

At what interest rate should debt be used as a tool?
It's not so much the rate of the debt as it is the total cost of the debt relative to the gain you expect to see from using it to purchase something of value. I've known people who were quite happy to pay 12% on personal loans used to buy investment properties for flipping.  They're happy to pay that because conventional loans from banks require too much documentation and out-of-pocket expense.  For some investors, 12% without all of the documentation burden is money well spent. So if I'm the investor, and the interest on this 12% loan is $5,000 and I can flip a property for $20,000 after all of the other expenses, then the 12% loan was an enabler to netting $15,000 profit.