CBO's Estimate for Senate Amendment 2123, an Amendment in the Nature of a Substitute to H.R. 3237, the Emergency Security Supplemental Appropriations Act [open pdf - 130KB]
From the Document: "Senate Amendment 2123 would provide supplemental appropriations for federal agencies and the legislative branch to respond to events at the United States Capitol that occurred on January 6, 2021. The legislation also would provide supplemental appropriations to legislative branch agencies to prevent, prepare for, and respond to impacts of coronavirus. Those amounts would be designated as emergency spending, in keeping with section 251 of the Balanced Budget and Emergency Deficit Control Act of 1985. The limits on discretionary budget authority established by the Budget Control Act of 2011 (Public Law 112-25), as amended, would be adjusted to accommodate such spending."
Congressional Budget Office: https://www.cbo.gov/