Each piece of form plywood is a hefty 50 dollars or so.  But the ecological impact of manufacturing a sheet of this ply will only be felt by future generations; not the fabricator or the user. My influence on the well-being of the environment is in the total use and re-use of this material, regardless of the profit margin. Do you understand? We throw re-useable things away every day, because it's not convenient to think about them after they have served their initial purpose. My construction-industry-ruined crew were constantly grabbing for the new sheets, right next to the pile of stripped forms. They were trying to be efficient.