Although Costco is known for having top brands and products at special, members-only prices, the retailer isn’t immune to the holiday sale extravaganza every few months. Holidays such as Black Friday and President’s Day are typical times that offer big savings. Your buying options will be more limited if you shop solely at Costco. For example, even among the brands they do carry, you won’t be able to hand-pick the exact Casper mattress model you’ve been eyeing, as Costco only carries the store-exclusive Casper Select in its hybrid and memory foam models.