Emergency medical care is expensive. Don't use it for routine problems like colds and flu. Live within walking or biking distance to school. Check notice boards around campus for secondhand bikes for sale. Don't buy a used car unless you are knowledge about mechanical stuff.
Car repairs can be very expensive.
Take the campus bus, or Bloomington transit. Having a car is not that important. I know that my friends always buy brand-name products, premium gas, and go out to dine. Even with financial difficulties, they keep doing that. I guess it is not easy to change one's values, but I think that the kind of values you have are the key to surviving here.