Out of print and surprisingly scarce--until you realize Dark Horse is fairly well-known for under-printing the art books it publishes.
From the publisher:
From Don Bluth - master animator, artist, and director of such cartoon classics as The Secret of N.I.M.H., An American Tail, The Land Before Time, All Dogs Go to Heaven, Anastasia, and Titan A.E. - comes Don Bluth's The Art of Storyboard, a one-of-a-kind textbook that describes in detail the technical and artistic processes involved in crafting storyboards for animated films, the visual blueprints that lay the foundation for the animators magic.
Don Bluth takes readers on a journey as only an artist of such vast skills and filmmaking experience can, going from the breakdown of a script, through story conferences with Don Bluth Films collaborators Gary Goldman and John Pomeroy, and onto the finished boards. Loaded with technical tips and insights into the tapping of the creative imagination, The Art of Storyboard also features page after page of Bluth's beautiful storyboard illustrations, many in full color. Whether used as an inspiring tool for professional and aspiring animators or just for the sheer joy of seeing how the written word is channeled through the animator's mindscape on its way to the screen, Don Bluth's The Art of Storyboard is a fascinating peek behind the curtain of film's most creative storytelling medium.