On that basis, the record low levels of current mortgage rates do represent a good bargain. Even on a relative basis, if you assume that somewhere over the course of a 30-year loan interest rates will return to normal, anyone who locks in a mortgage at today's rates could find themselves borrowing for less than the bank pays for deposits over much of the life of the loan.

That's a good deal, so long as it doesn't become so systemic that it weakens the health of the banking system. If that happens, you can expect that consumers will pay again, in one way or another.