In year three of actual compliance, many companies have moved along the learning curve enough that the inside costs of compliance are dropping even more. A survey of accelerated filers by Financial Executives International has found that the average cost last year was $2.9 million. That's a 23 percent decline from the previous year. The number of in-house hours required for compliance dipped 10 percent. External hours dropped 14 percent. The big wildcard remains auditor fees, which fell less than 1 percent. Going forward, there is still a lot of uncertainty regarding such fees. A lot is riding on the new AS5, which is still in the works. It will take a lot to really induce auditors not to take an overly conservative approach. It also must be said that the big audit firms have really benefited from Sarbanes-Oxley through increased revenue. We'll see how easily they change their tune.   

For more:
- here's an article [1] from cfo.com