Walmart offers the LEGO Creator Treehouse Play Set, model no. 31010, for $23.21. (Kmart charges the same via pickup and Amazon sells it for the same price for Prime members.) Opt for Site-to-Store pickup to avoid the $4.97 shipping charge. That's the lowest total price we could find by $7. This 356-piece set includes two tree trunks, detachable treehouse with detachable roof, secret trapdoor with lock and red bucket trap, fold-down ladder, gray bucket with winch and storage area with a sleeping mat, and more.