I'd like to know too - the local place here is charging $180 for a sheet of 3/8" black cast, $159 for clear cast. Are others finding similar prices and differences between clear and colored?
It's Plexiglass. The one place in my area that uses Cyro only has the extruded. I picked through their scrap bin and they had plenty of Cyro extruded, but only Plexi cast. Choices in my local area are pretty limited.