Congressional investigations have no teeth.
As Inspector General, Mr. Horowitz oversees a nationwide workforce of more than 450 special agents, auditors, inspectors, attorneys, and support staff whose mission is to detect and deter waste, fraud, abuse, and misconduct in DOJ programs and personnel, and to promote economy and efficiency in Department operations.
sauce:
https:// oig.justice.gov/about/meet-ig.htm
Wikipedia:
There are 73 federal offices of inspectors general,[3] a significant increase since the statutory creation of the initial 12 offices by the Inspector General Act of 1978.[4] The offices employ special agents (criminal investigators, often armed) and auditors. In addition, federal offices of inspectors general employ forensic auditors, or "audigators," evaluators, inspectors, administrative investigators, and a variety of other specialists. Their activities include the detection and prevention of fraud, waste, abuse, and mismanagement of the government programs and operations within their parent organizations.
Why $1.5 billion?
73 * 450 = 32,850 people are employed by all of the OIG offices.
Seems like a goodbye in this context.