If my teeth don't hurt from grinding do i have to repair them? which is the cheapest option? i'm a poor grad student.

OTC night guard: I would suggest buying an OTC night guard first, keep you from damaging your teeth. You can also buy a high quality custom-made night guard from your dentist at a later time.

Abrasion?: Are your teeth ground down from your bruxism? If so, the least expensive solution, right now, is to have a bruxism guard fabricated. This will stop the damage. When you graduate and are making the big bucks, you can consider restoring your teeth.

Grinding: Grinding will cause damage to teeth, supporting tissues, and eventually the jaw joints. By the time it hurts damage may be severe. See your Dentist to evaluate current damage level. Perhaps cause of grinding can be discovered and I expensively eliminated. A night guard may be a good band aid to protect teeth from further damage.