The researchers found that US$86 billion ... were saved in personal health care expenditure between 1989, the start of the [California Tobacco Control Program], and 2004. This generally grew over time, reaching 7.3% of the total in 2003–2004. The personal health care expenditure savings represented about a 50-fold return on the $1.8 billion spent on the program during the same period (all 2004 US dollars).
That's from the Editor's summary of this PLoS Medicine article by James M. Lightwood, Alexis Dinno, and Stanton A. Glantz.
Hat tip to Seema Singh.