To go about 2500 miles in the last year, I bought a single-speed bike on sale for $160 from Nashbar with free shipping and a special 20% one item email coupon, then bought some blow out brakes, alloy seat post, comfort saddle and new tires for about $100 more. $260 for 2500 miles is a bit over 10 cents per mile. It also saved me about 100 gallons of gas if I drove my old pickup or minivan (@$4/gallon = $400) which I then traded in to buy a new Prius V, which now makes it such that my bike communting only saves me about 58 gallons of gas, which is about $230. But next year, I figure my annual maintenance costs for the bike should only be $40 for new tires, tubes, new gloves, batteries/lights accessories. (I ride cheap michelins or kendas).

As for time, my own time isn't worth much. The company pays me for intellectual property and it's project based on a schedule. If I get it done sooner, my time is still worthless. But that said, riding 6 miles to work only takes about 25 minutes door2door. Driving the 9 freeway/expressway miles takes about 12 minutes, but then takes another 15 minutes hunting for parking and hiking back to the office across campus. So it's a wash. I have a bluetooth headset in my ear while riding. And my car has bluetooth. Both get internet radio whether I'm in the car or riding my bike. Yes, riding does have the disadvantage that if my manager calls in, there's a heck of a lot of wind noise on the ear piece, while the car is whisper quiet and I have air conditioning. But that only happens rarely.

So in a time and economics comparison, I think bike commuting completely wins, just based on gas prices alone with time being the same. I don't need liability or collision/comprehensive insurance for my beater clunker, and while I do standard things like oil changes and filter changes for my cars, tuning up the bike is a LOT cheaper and faster. Certainly I have expensive road bikes. But rather than paying $thousands, I buy them for sub $1000 or may around $600 on CL or eBay and fix them up. It would still make commuting by bike cheaper, over time.