Walmart.com: K’NEX Sets for just $10! September 18, 2011 by Jennie The links in the post below may be affiliate links. Read the full disclosure.Print Email Walmart currently has K’NEX 325 Piece Super Value Tubs or Kid K’NEX Big Building Tubs on Rollback for just $10, with FREE site to store shipping! I’m sure that these will sell out quickly, so snatch them while you can. I’m sure that these will make some great additions to your Christmas stockpiles.