Rear End on 2001 Mercedes-Benz SLK320

I am getting a lot of noise (road noise and rear end noise). At first I thought it was the tires, but it is getting worse. Rear end bearings maybe? Or....How much?

Asked by for the 2001 Mercedes-Benz SLK320
Usually when a rear end (differential) is failing it will make a roaring sound either when accelerating or decelerating and a wheel bearing will usually have a constant rumble type of noise and you can get the wheel bearing replacement price here