Not sure what you're referring to but my best guess is anti-sway bar links. In true GM fashion, the left and right links are just a little different so two part numbers are needed. That adds a little cost to the parts. This type of design is relatively difficult to remove compared to other designs so you can expect them to take around a half hour each. The links cost around $30.00 from aftermarket sources and around $40.00 from the dealer. Those are estimates based on similar parts for Chrysler products, although on Chryslers and Fords, the left and right sides use the same part. GM parts always cost more. That's one of their many ways to separate you from your money after the sale.
There are anti-sway bar links on the rear too. They cost a little less but are more difficult to remove so it would take longer.