Old books are very collectable. First editions, verified signed copies, and the biggie, this is why it has no real cash value, the book must be the authoritive or offer up the last word on a topic to retain monetary value. In other words the existence of this forum means the book has a low monetary value. But don't let that be the thing that sticks in your head. I'd go through the book and keep it off it has day really good pictures, really good anatomical photos of weed are still, even with the internet, kind of hard too come by; many new books are plagued by this issue.