That's a little cheaper per bearing/hub combination than what I paid for
mine at the dealer.  I think it's in the ballpark of reasonable, for a
reasonable definition of reasonable. :-)

Why, exactly, do they want to do the hubs too, though? Make sure you
tell them you're going to ask to see the old hubs after they're done to
make sure they're truly damaged or rusted to hell.

With places like Firestone or even the dealer they'll like to replace
the entire assembly, which is why you're paying for the bearing PLUS
the hub on each side. No reason for a tech to change the CV boot and
clean the joint when he can swap in a half shaft in no time.

Call the dealer/local shops and ask how much for pressing out the old
bearing and pressing in the new, see the free repair guide on
Autozone:

http://www.autozone.com/az/cds/en_us/0900823d/80/15/75/e7/0900823d801575e7/repai
rInfoPages.htm

You can then elect to buy bearings from the dealer or online. Should
be no need to change out the hub.