Post up prices that you find. If someone can get the part #'s, you can check it on gmpartsdirect.com yourself.
When I get home I can look in the parts manual and see IF GM still sells them, how much they cost. Of course, only if you can't get the part numbers yourself. Your local dealer can probably do that over the phone (if they aren't too lazy/stupid like 90% of GM parts people) but if anything like mine, you will pay retail on them, so get a part number and check it against GMPD.