Interesting thought, treating your debt like a bond.

If you no longer need the debt, i.e. you have the cash to pay it back, you could _theoretically_ loan out that cash to someone else at the higher current market interest rate. Loaning money involves credit risk of course, so practically this would mean buying something like higher interest paying Treasuries or AAA bonds. Effectively, the spread between your borrowed fixed rate debt and the bonds you bought are the _profit_ you make, the NetPresentValue of which is roughly what you would get if you could "buy back" the debt.