looking for ball joints for my c280, why such wide range in prices 6.97 / 100.00 on 2000 Mercedes-Benz C280

why such a wide range in prices, what am i looking for? and engine mounts, how many mounts does this vehicle requires?

Asked by for the 2000 Mercedes-Benz C280
there are alot of cheap parts out there and they will not wear like the better parts. this could be a safety issue so i rec good high quailty parts for suspension. in this case don't cheap out