Walmart has started their holiday Rollbacks already, with lots of great deals! You can pick up this K’NEX 70 Model Building Set for only $16.98 right now! This normally sells for $39.97, so that’s a pretty huge savings on a pretty big set of K’NEX! This set includes 750 pieces and 70 building ideas. Pick this up at your local store for free, or get free shipping on orders of $50 or more.