I found mine for $7.50 a piece at a metal scrap yard. Just had to wait till they got a new load of unlined in. Mine were stamped "Biodegradable Kosher Coconut Oil." They were closed top and my Weber lid fit perfect.
Call around to a few scrap yards and if they don't have any in ask'em if they have any recommendations as to where else to try. They normally know everyone else in the business in the area and are willing to refer to each other for items they don't carry. While your there ask about expanded metal too.