Here's a new B1G1 coupon for Diet Pepsi (2-liter). I don't have current prices other than it's $1.25 at Target (through 2/16) and $1.50 at Bashas' (through 2/19).
This coupon has an HEB logo on it, but it's a manufacturer's coupon, so most stores will take it. I don't shop at Bashas' very often, so I'm not sure. I'm guessing it will vary at Target stores. I've never had a problem with other logos at Fry's, so you may want to check out their price. (Leave a comment if you know, please. Thanks!)
You can also print a 50¢ coupon for reg. or diet, 20 oz bottles of Dr. Pepper. I think these are about $1.49 – $1.99 most places, but I'm not positive. All I know, if I think they're expensive. But, if you're looking for convenience, it may be worth it. (If you know the best place to use it, please leave a comment. Thanks!)
(Thanks, Printable Coupons & Deals!)