The cost to replace a ball joint can vary depending on your vehicle, the parts required, and the labor involved. The part itself can be relatively inexpensive, but labor can add significantly to the total cost because the suspension must be disassembled to access the ball joint. On many modern vehicles, ball joints are built into control arms, so you may need to replace the entire arm rather than just the joint, which raises the cost. It is also common to replace ball joints in pairs on the same axle. Altogether, you might see a range of a couple of hundred to several hundred dollars per side for parts and labor.