I took the bus or subway 42 days, but I paid an extra fare for the express bus 9 times. Thus I paid 93 fares for 42 days. At $2.60 per fare, my average daily bus cost was $5.76. Had I spent that on each of the the 161 days I biked, it would have totalled $926.90 in bus costs. So that is how much I can spend on bike-related costs every year and still ride as cheaply or cheaper than the next best alternative.