BestBuy has a price-match program where you can go in the store and show them a product advertised online at one of their competitors and they match or beat the price instantly.
Price Match Guarantee
The online version is similiar. Instead of "finding a blueshirt" (BestBuy salesperson), you connect with one online via their chat messenger option. You show them the website or online ad and they take it from there.
You can buy online and pick up on location to enjoy extra savings.