The last few posts here have been about the MORE Act, legalizing marijuana, and taxes. Here and below are official budget numbers for the MORE Act, which passed the House yesterday: https://www.cbo.gov/system/files/2020-12/hr3884.pdf.
A quick tax, taxes first:
“CBO and the staff of the Joint Committee on Taxation estimate that H.R. 3884 would increase revenues, on net, by about $13.7 billion over the 2021-2030 period by creating business income, compliance, and occupational taxes; those increases would be partially offset by allowing certain deductions for business expenses associated with trafficking controlled substances.”
That $13.7 billion comes from two sources: an ad valorem excise tax, picking up $5.677 billion, and general revenues like income taxes that come from opening up the marijuana market to legality and the light of day, and picking up $8.013 billion. The latter number would be greater if 280E, disallowing those business expense deduction, were in place. A 2017 estimate of 280E repeal was that it lost $5 billion over 10 years – for a 10-year period when legalization was less widespread. https://newrevenue.org/2018/12/17/official-280e-revenue-cost-5-billion-over-10-years/. That number should be higher than $5 billion now. Keeping 280E (or reinstituting it) and foregoing the excise tax might yield more revenue.
The bill would reduce the deficit by about $ 1 billion over 5 years, and by about $7 billion over 10 years. Most of that impact comes from the $8 billion in “other” taxes like post-280E income taxes; the excise taxes are spent, via trust fund operations.
Other stuff:
Other budget impacts include savings from less incarceration: “reducing both the number of inmates in federal facilities and the aggregate time they serve would result in net savings of about $1 billion over the 2021-2030 period.” “CBO estimates that H.R. 3884 would reduce time served by 73,000 person-years, among existing and future inmates.” Calculating, that’s a cost of about $13,700 per person year. I thought incarceration cost more than that. Anyway, prisoners aren’t eligible for federal programs; lessening the prison population and freeing folks up for programs is estimated to cost $636 over the period.
The Center for New Revenue 
The cost per inmate per year in a federal facility was $37,449 for 2018.
https://www.federalregister.gov/documents/2018/04/30/2018-09062/annual-determination-of-average-cost-of-incarceration
Also worth considering is that freeing so many people from prison will obviate the need for new prison construction for a number of years.