This got me to thinking.
I commute around 10 miles a day, which is 300 miles a month. It's actually a little more than that, what with random grocery trips n such, but I digress.
My 4runner gets about 15 miles to the gallon, so that's about 20 gallons of gas per month. If gas is 4 dollars per gallon, that's around 80 dollars per month, just in gas, not counting oil changes, tires, etc, which all add to the price of driving, here's a more realistic calculus for the cost of driving a car.
My xtracycle cost me around 400 dollars back in November. If it hasn't paid for itself by now, it will have by the end of the summer.