Sears offers the Ultra Plus Powder Laundry Detergent 275-Load Box (26.4 lbs.) for $15.99. Opt for free in-store pickup to avoid the $21.59 shipping charge. That's $0.06/load, $11 off, and the lowest price we could find, although we saw it for $3 less in February. This detergent is rated for high efficiency use in all washer types.
Of note, Shop Your Way Rewards members may earn a Sears credit with this purchase and may be eligible for additional credits and discounts.