Walmart offers the Master Mark Plastics Raised Garden Bed Starter Kit, model no. 99514, for $25.84. (Amazon charges the same with free shipping for Prime members.) Choose in-store pickup to avoid the $5.99 shipping charge. That's the lowest price we could find by a buck. The kit includes four stackable corner mounts that will hold 5"-tall boards with a thickness between 11/16" and 1". (Boards are not included.)