Congressional Budget Office Cost Estimate: H.R. 5602, Domestic Terrorism Prevention Act of 2020 [open pdf - 76KB]
This is the Congressional Budget Office Cost Estimate as passed by the House of Representatives on September 21, 2020. From the Legislation Summary: "Under current law, the Federal Bureau of Investigation (FBI), the Department of Justice (DOJ), and the Department of Homeland Security (DHS) investigate, prosecute, and work to prevent acts of terrorism--both domestic and international in nature. H.R. 5602 would require each of those agencies to create new offices dedicated to investigating and preventing domestic terrorism and would authorize the appropriation of whatever amounts are necessary for those offices."
Congressional Budget Office: http://www.cbo.gov/