In its latest report on the Troubled Asset Relief Program (TARP), the Congressional Budget Office dropped the estimated cost of the program substantially.  The CBO's estimate is now $25 billion.  That's a far cry from the estimate of $66 billion in August, or $109 billion from the CBO's March report.  There is some explanation for the cost trending downward at the CBO's Director's Blog:

It was not apparent when the TARP was created two years ago that the costs would be this low. At that time, the financial system was in a precarious condition, and the transactions envisioned and ultimately undertaken through the TARP engendered substantial financial risk for the federal government. However, the cost has come out toward the low end of the range of possible outcomes anticipated when the program was launched. Because the financial system stabilized and then improved, the amount of funds used by the TARP was well below the $700 billion initially authorized, and the outcomes of most transactions made through the TARP were favorable for the federal government.

Some more specific reasons:

-Additional repurchases of preferred stock by recipients of TARP funds; 

-A lower estimated cost for assistance to AIG and to the automotive industry; 

-Lower expected participation in mortgage programs;

-The elimination of the opportunity to use TARP funds for new purposes (because of the passage of time and the provisions of the Dodd-Frank Wall Street Reform and Consumer Protection Act).

Read the full report here.