Sam's Club offers its members the OxGord BazooK-9 Tennis Ball Launcher Bundle for $9.81 with free shipping. (Non-members spend an extra 98 cents. Alternatively, Paws & Pals via Amazon has it for about the same price.) That's the lowest price we could find by $4. Designed for playing with your pets, it comes with two squeaky tennis balls and features a shoulder strap.