Walmart has the K’NEX Raptor’s Revenge Roller Coaster Building Set on Rollback today for only $17.88 right now! (Reg $34.99) This set includes 617 pieces, which creates an awesome roller coaster with over 19 ft of track, and a motorized coaster.
Pick this up at your local store for free, or get free shipping on orders of $50 or more.