Walgreens.com right now has their regular buy-2-get-1-free promotion on hair care products, including Rogaine. Regular price for the 3-pack is $ 53.99. They also always have their welcome code for new accounts, 15WELCOME, for 15% off the first purchase with a new account.
And there is also the $ 10 coupon if you purchase with VISA Checkout (I think this exists at all times, but this coupon is one use per account, so if you have used it previously you won’t see the opportunity to add it).