Sears offers this Ultra Plus Powder Laundry Detergent 180-Load Box (17.3 lbs.) for $11.99. Choose in-store pickup to dodge the $17.62 shipping charge. That's $0.07/load, $12 under list, the lowest price we could find, although we saw it for $2 less last fall. This detergent is rated for high efficiency use in all washer types.
Of note, Shop Your Way Rewards members will earn a Sears credit with this purchase and may be eligible for additional credits and discounts.