Groupon offers this Men's Waffle-Knit Thermal Shirt 4-Pack in four color assortments for $34.99. Coupon code "JUMBO3" cuts it to $31.49. With free shipping, that's $2 under our mention from two weeks ago and the lowest total price we've seen. (It's also $8 under the best deal we could find for four similar shirts elsewhere, excluding the mention below.) It's available in sizes M to XXL, although not in all size/color combinations. Deal ends January 21. Update: The price has dropped to $27.99 before the above coupon, $25.19 after

A close price: Walmart offers the Hanes Men's X-Temp Thermal Underwear Crew Tee in four colors for $8 each. Opt for in-store pickup to dodge the $4.97 shipping charge. It's available in sizes S to XL.