I ordered up a monthly bus passport today. $25 monthly gives me unlimited bus usage. I have solid documentation indicating I fill my car with gas twice a month for $30-ish. So I break even if I end up filling once a month. I'm not convinced I can do that but time will tell.
It turns out I've joined a select group. The nice woman in charge of shipping monthly passports to subscribers kindly answered my question...she mails 15 passports a month to riders like me. That's roughly 1/100th of a percent of our population. She also mails a fair number for state programs like disability which agrees nicely with my previously stated perceptions.