$163? for what? coro doesn't cost that much from harbor sales. I recall is being less than $10 for a 4x8foot sheet, plus a small cutting fee to make it small enough to ship.
http://www.harborsales.net/fullsheet...ts#productview
is the url for the coro product selector. It shows a 4x8 2mm sheet for $15.39, so prices are up a bit since I last bought any. On the other hand, some 4mm colors are as low as $8.14 for a 4x8 sheet.
And, something new on their website, you can order smaller sheets already cut, such as 36"x24" and smaller. They didnt used to do that.
I have no idea what you did to get that much money for a sheet of coro, but it wasn't what I was talking about.