Why is Clear Extruded acrylic cheaper than Clear Cast acrylic?

Cast acrylic is generally regarded as a better quality material and offers a number of advantages over the extruded variant such as having a higher optical clarity and superior surface finish, being more resistant to chemicals and solvents, less prone to scratching, easier to machine and fabricate and available in a far wider range of colours and surface finishes i.e. gloss/matte. The manufacturing process for cast acrylic is longer and more complex than that of extruded acrylic which in-turn generally makes extruded acrylic slightly cheaper.