Target offers the Downy 129-oz. Ultra April Fresh Liquid Fabric Softener for $8.99. Tick the box marked "save 5% when you subscribe" to cut it to $8.54 and bag free shipping. That's the lowest total price we could find by $6. It contains softener for up to 150 loads.
Be sure to cancel your subscription at Target after the item ships; otherwise, you'll be billed for future shipments.