Before I would spend time and money on fixing the ball joints, I would get a second opinion. They might be trying to rip you off. It has happened to me once back in the mid 80's on a new car. All I wanted was a front end alignment. I took the car to another garage and nothing was wrong. I drove the car another 130,000 and never did change out the "bad" parts. They were trying to rip me off.