For in-store pickup only, Toys"R"Us offers the Nerf Super Soaker FreezeFire 2.0 Water Blaster for $6.39. That's the lowest price we could find by $7. It features a 20-oz. tank and blasts water up to 38 feet.
A close price: Kohl's charges $7.19 with in-store pickup via the coupon code "SPLASH20".