Amazon has 2-Pack 12.8oz Head & Shoulders Men’s 2-in-1 Dandruff Shampoo w/ Charcoal for $6.96 when you ‘clip’ the $1 off coupon located on the product page and checkout via Subscribe & Save (select the later date from the "First Delivery On" menu). Shipping is free.
Note, coupons are typically limited to one per account. You may cancel Subscribe & Save any time after your order ships.