I don't know about the cost but the benefit is close to zero, if not zero. I am positive that the net benefit (because cost is surely positive) is negative accounting even for the number of jobs it creates.

> The source did not give an exact number, but said the failure rate was close to 80 percent. Members of Congress called the results "disturbing" in a public hearing following a private, classified briefing to the House Committee on Homeland Security.

https://www.usnews.com/news/national-news/articles/2017-11-0...

archived at https://web.archive.org/web/20221116171835/https://www.usnew... https://archive.ph/hzA1y