Updated on 03/12/2018. Costco offers $5 off on this item, dropping the price to $19.99; price is valid from March 15, 2018 through April 08, 2018. Costco Coupon Book: March. 15 – April 08, 2018 Keep your beverage cold all day and hot for 12 hours with this Thermoflask Water Bottle. Its double-wall vacuum insulated stainless steel prevents outside temperature from […]