Car

I'm currently looking at wasting $1200 per year on the bus. And assuming that I go during rush hour, two hours of wasted time in traffic. If I get paid $30 per hour, that's $60 per day right there. Multiplied by 49*5, a yearly loss of $15000. Alternatively, I can/should get (someone else's) upass, and only pay $20 per year.

Now, the alternative is to buy a car. If I commute before the traffic sets (arriving at 8 and leaving at 4), I can get to work in roughly half the time (or perhaps 20 mins one way), thus only wasting $7500 per year in utility-dollars. What are the sunk costs?

1. Insurance - roughly $1500 per year.
2. Gas - Suppose I have a car doing 20 miles per gallon. That's very roughly 10 km per liter. If gas prices are $1.5 per litre, and commuting to work and back is roughly 40km, I'm looking at $6 daily, or 6495 = $1500 per year. I can probably do better though, with a car that does 40 MPG, such as a geo metro. The number goes down to roughly $750.
3. The car itself - Can probably get something for like $3k
4. Parking should be free, but may be 60*12 = $720 a year.

Should I buy a car?