I have no idea, so I did a search for it, and found a "review" of the boards in question.
http://andrewwales.blogspot.com/2008/02/create-your-own-comic-book.htmlIt looks like you can get the stuff cheaper online at
http://www.dickblick.com/products/canson-fanboy-comic-and-manga-papers/ at $11.67, plus a minimum of $6.95 for shipping (unless you plan on making a purchase of over $200), it ends up being $18.62, which is, what? $2 Cheaper?
I checked a couple other online retailers, and they all stick to a $20 cost, so I guess, yeah, $20 sounds about right.
(Though, my dad works in paper, and I know that that is WAY more than what the paper actually costs. Must be the blue ink, or the plastic wrapping.)