Amazon offers Prime members four Old Dutch 16-oz. Copper Moscow Mule Mugs in Smooth Finish for $22.01 with free shipping. (Non-members can spend $49 or more to qualify for free shipping; otherwise, shipping costs $7.79.) That's $4 under our March mention and the lowest total price we could find by $27. Each mug is lined in nickel and coated with tarnish-resistant lacquer.