Suarez pointed out in his note that the cost to the county would be small: “Given the fact that total revenues from buses and Metrorail barely exceed $100 million, which is less than two percent of the operating budget for the county, the time has come to induce the use of mass transit by any and all means.”
...Suarez has asked the county attorney’s office and the county transportation planning organization to study how both Kansas City and Salt Lake City approached the issue of free public transit. Two candidates in the Utah capital’s August mayoral primary pushed the idea of free citywide transit, and while the ultimate winner in the November runoff election pledged to work on improving the quality and frequency of service first, she has also proposed expansion of free transit to more local residents. Salt Lake City already has a fare-free zone in its downtown.
Currently, 32 cities and towns in the United States operate free transit systems. All of them are significantly smaller than Salt Lake City, Kansas City or Miami-Dade County.
Yes, he said two percent. But that is "operating" cost. What about capital cost? Usually in big systems, operating and capital costs are about equal, meaning that fare account for on 1 percent of total costs.
https://nextcity.org/daily/entry/will-free-transit-fever-spread