2000 Other Jeep Models Shaking Front End

Whenever I hit a pothole, or a bad bump at highway speed, the front end shakes pretty bad. You feel the vibration is transferred to the steering wheel. This is a full time 4wd, you have 4 hi and 4 low only. It also makes a sound like the tires are rubbing when you turn it sharply, especially to the right. How bad are these repairs going to bite me?