Walmart discounts a selection of rollback and clearance laptops, tablets, phones, HDTVs, and other electronics. Choose in-store pickup to dodge the $5.99 shipping fee, or spend $35 or more to qualify for free shipping. A couple of best bets, both with free shipping:
Epik Learning Tab Jr. 7" 8GB Android 6.0 Tablet for $49.98 (pictured, low by $20)
LG Stylo 2 Prepaid Android Smartphone for Boost Mobile for $79.99 (pictured, low by $20)
If you aren't using any of these three methods for significantly saving on laundry detergent, you are washing money down the drain.