K’NEX Plastic Typhoon Frenzy Roller Coaster Building Set for $19.99 shipped. To get free shipping, you simply need to sign up for Staple’s rewards program, which is free and easy. Here is a screenshot for your reference. K’nex Typhoon Frenzy Roller Coaster Building Set contains more than 640 durable plastic pieces. It features a 2 AA batteries operated motor for mechanical movements. Most places have it for about $37.