Amazon offers Prime members the K'NEX Star Shooter Coaster Building Set for $14.99 with free shipping. (Walmart has it for the same price with free in-store pickup. Non-Prime members can spend $35 or more to qualify for free shipping; otherwise, shipping adds $6.53.) That's the lowest total price we could find by $7. It includes 434 parts for building your own amusement park rides. Two AA batteries are required, but not included.