TARP is just one of many bailout facilities. There are others by the Fed, for example Quantitative Easing. Another is allowing banks to essentially print money by allowing them to borrow from the discount window and immediately then park the cash into higher-yielding assets.
The cost was not low -- rates dipped below 1% because the Fed printed money. But printing money is not free. The common person pays for it by earning less on savings and in the form of inflation, especially retirees who diligently saved through their lives hoping to earn and live off interest in their old age. Every person purchasing a house pays more for low rates because housing prices go up, so do all the associated fees which are on the Notional value (e.g., title insurance.) Pension funds "pay" for it because they cannot easily make money via bonds any longer.
