_DealGroup版 - 【$】Tide ColdWater HE Fresh Scent with Actilift, 50.0-Ounce Bottles (Pack of 6) $27.55 AC S&S or Tide Free and Gentle High Efficiency 75.0 oz (Pack of 4) for $29.55 S&S @ Amazon
I don't know how pricing compares across different brands and varieties of
detergents, but this seems like a good price based on a search of prior
deals that were ~0.09-0.10/oz. Clip $2 coupon and select Subscribe & Save
for final price of $27.55 for six 50-oz bottles (~.09/oz).
Link: http://www.amazon.com/gp/product/B002SB95FK/