1997 Other Jeep Models Rear bearings

I'm desperate for answers. I took my Grand Cherokee in for repair and they told me they were replacing 6 (six) rearing bearings for $1200. Are there more than 2 wheel bearings and 2 differential bearings? Is $1200 reasonable? Now they have told me that the rear axle shafts, four brake rotors and parking brake shoe must also be replaced for an additional $1000. They said the axle shafts new cost $700 each, but would try to find two used axles for $600. I called a 4x4 parts place and was told I could buy two new axle shafts for $500. I'm so confused and am wondering if I am not asking the right questions. Please help. Thanks