Walmart offers the Contigo SnapSeal Byron 20-oz. Stainless Steel Travel Mug in Gunmetal for $6.39. (Amazon charges the same.) Opt for in-store pickup to avoid the $5.99 shipping charge. That's tied with our expired mention from two days ago and the lowest price we could find for this color by just under a buck. It keeps drinks warm for up to seven hours and cold for up to 18 hours.