Shelving with no decking can be shipped for less. You can purchase particle board from a local source and save on freight, or utilize other decking materials of your choice (be advised that listed capacities are calculated for evenly distributed loads with standard decking materials)
Shelving with decks included comes complete with metal structure and 5/8" particle board cut to size for easy, drop-in assembly. All decking and needed hardware is included, so it's ready to assemble as soon as it arrives.