Amazon offers the Reach Complete Care 8-In-1 Plus Whitening 32-oz. Mouth Rinse 4-Pack for $21.12. Clip the 50% off coupon on the product page and check out for a final price of $10.56. (Enamel Restore is available for a few cents more.) Plus, Prime members receive free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, shipping costs $5.48.) That's $13 under what you'd pay in-store locally for this quantity. It features a pump, toothbrush holder, and dosage cup.