Did you account for the flute direction when you say 19x48, the flutes are in the 48" direction?

Remember that you need do pieces to total up to a 4x8foot sheet.

I just did a run on their website. White, 2mm coro, 1 4x8foot sheet cut in to 4 24x48 parts. You can trim down to 19" on your own easily enough.

Total, including cutting charges and shipping to maryland is $19.26. Less than twenty bucks. Pricy for a single sheet, but it goes down if you get many sheets at a time.

Checkout should look like this: