I checked out the soda section at Target today and spotted two liter bottles of Fresca, Seagram's, Sprite and Diet Sprite with coupons hanging around the necks of the bottle. The soda was on sale for $1 each and the hanger is a manufacturer's coupon for $1 off 2 bottles.
Buy 10 of these bottles, use 5 of these hanger coupons, and stack with the Buy 4-Get-1-Free Coca Cola brand Target coupon here (click on the "grocery" tab).
Here's the math:
10 bottles @ $1 each: $10 5 manufacturer's coupons for $1/2: -$5 2 Target B4G1 coupon: -$2 Total, ten 2-liter bottles for $3 or $0.30 each.