I found large boxes of Emergen-Zzzz with Melatonin on clearance for just $3.37 at Walgreens. Buy one box and use a $2.00 printable manufacturer coupon to pay $1.37!
Note: Clearance varies by store.
Or buy two small boxes, regularly $5.00 each when you buy at least two. Stack two manufacturer coupons with a $1.00 Walgreens coupon from page 68 of the August Savings Book, available in the front of the store near the weekly ads. One Walgreens coupon will automatically apply to both boxes. Pay $2.00 each!