Walmart offers the Ozark Trail 30-oz. Stainless Steel Tumbler, model no. 83-492, for $9.74. Opt for in-store pickup to avoid the $5.97 shipping fee. That's tied with our mention from a week ago as the lowest price we've seen. (It's the best deal now by $3.) This BPA-free tumbler is double-walled and vacuum-sealed.