I would have to say the rotors are very bad. If it shakes that much I doudt they can turn the rotors enough to make for smooth braking. Cost for rotors. High. Could also have a collasped steering column. Could have. For about $30.00 you can drive into an "Express Oil Change" and they can hook your engine up to a monitor and check many items that maybe wrong. That is a very good price providing the car has been well cared for, but I don't think that it has. You could also need front "struts", which will eat at your pocket book.