For its Balance Rewards members, Walgreens takes $2 off a selection of Crest toothpaste when you clip the $2 off coupon found on product pages. (Not a member? It's free to join.) Plus, take an extra 20% off select varieties via coupon code "SENDOFF". (This discount applies the original price; eligible items are marked.) Combined, that drops prices for many options to under $1, starting as low as 39 cents.