Firefly Buys via Amazon offers Prime members the Nerf Super Soaker Electrostorm for $7.49 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $4.80.) That's the lowest total price we could find by $10. It shoots up to a purported 25 feet.

Also available for Prime members from The Dus via Amazon is the Nerf Super Soaker Electrostorm Showdown Set (pictured) for $13.50 with free shipping. (Non-members can spend $35 to qualify for free shipping; otherwise, it adds $5.35.) That's the lowest in-stock price we could find by $11. Update: Dragonshop via Amazon now offers it for $13.25 with free shipping.