2004 Chevy Malibu Ball Joints

My 04 Malibu Maxx needs replacement ball joints. I have discovered that there are just the ball joints and also the ball joint with control arm . The cost for ball joints are around $55 each and the joint with control arm is around $100 each. From what I can tell, places charge 3 to 4 hours of labor either one I choose. Is is easier to replace one over another?
The place I took it said the control arms were okay. When I called GM dealer, they said the only choice I had was the ball joint with control arm assembly.

Thanks in advance
rmd735