We absolutely do sell these and the price generally reflects the basic installation prices. Be sure to talk with the technicians to make sure there aren't going to be any additional parts/labor necessary to complete the install and for a more accurate price quote. Depending on the type of vehicle, you may need a pair of antenna adapters in order for the part to properly interface with your vehicles factory antenna system.
While I am employed by Best Buy for the Geek Squad Automotive Technicians, my responces are strictly my own and do not represent those of Best Buy formally or informally.