Real collectors and dealers wouldn't handle books worth $1,000,000 without gloves, and they surely wouldn't smoke or drink wine directly over them. Also, a book that old (not to mention the XVIII century Don Quixote volumes he takes at the beginning) would not resist the way Corso keeps chucking it in his bag or the fact everybody seems to be handling around. Furthermore, no dealer in his right mind would try to photocopy a four centuries old book by placing it in a commercial machine face down and pressing it as depicted in the movie: such actions would inflict severe damage to the printing and binding, drastically affecting its worth. Regardless those characters who see the book as a tool rather than a priceless collectible, Corso and the brothers Ceniza are experts in the matter, and would never treat such rare and priceless books that way.