We have some nice Scotch-Brite deals over at Amazon. There are a few 6-packs deeply discounted, plus they are eligible for subscription discounts and have coupons on the product pages too. Pay as little as $0.63 per sponge.
Scotch-Brite Non-Scratch Scrub Sponges, 6 Scrub Sponges – only $3.75 ($0.63/sponge) with sale, subscription discount and $0.56 coupon on product page (reg. $9.65)
Scotch-Brite Greener Clean Non-Scratch Scrub Sponges, Made from Plants, 6 Scrub Sponges – only $3.76 ($0.63/sponge) with sale, subscription discount and $0.40 coupon on product page (reg. $8.47)