Rear wheel bearing replacement question

[onkauai]

I got a quote to have the passenger side rear wheel bearing replaced for $1500 - $95/hour charge with I think $972 in parts and $500 in labor. They are telling me that I should replace both the wheel bearing and the axle when I replace the bearing. Seems odd that the axle itself needs replacing. Does anyone have any thoughts on this? Looking at the Bentley manual, it looks like a big job if I do this myself.