Walmart offers an Ozark Trail Value Bundle which includes 28L Atka Daypack + 30-oz Double-Wall Vacuum-Sealed Tumbler (Stainless Steel) for $7.12. Free store pickup where available or shipping is free on orders $35+. Thanks SkydivingSteve
Note, you must choose the Tumbler in Stainless Steel to get the price listed.
Walmart has the Ozark Trail 30oz tumbler with the Atka Daypack for a total price of $7.12. (normally $16.84 if purchased seperately) Price is for the stainless steel tumbler, free store pickup available or FS @$35.
The Atka daypack is on sale for $10.84 and the tumbler for $6, so this saves you roughly $10.