getting a beater is only stupid if you can't afford it, as I mentioned above - You should only get one if you have the money. Most people I know either don't live on campus, or if they do, they have a beater or they leave their cars at home. When it comes down to it, it depends on two things.

1. how safe/secure is your campus? check out the schools website & newspaper and see if there's a history of senseless vandalism. My school publishes a police notes section in their paper, which ALWAYS includes at least a couple reports of vandalism to cars.

2. how paranoid are you? If you constantly worry about your car and/or have to check up on it to make sure nothing has happened to it, you should get a beater to save yourself the worry.