In a WTB thread for a high grade FF52, someone said to wait for the book to fall. I made these comments, which I think apply to this discussion.
Normally, I would agree with you, but this issue has some special, long lasting appeal to it. In a typical movie scenario the prices spike before the movie and immediately cool off afterward. With this book, the prices seem to be rising more after the movie. I think it was a bigger hit than anyone imagined and there will be more movies coming. It's truly rare in the high grades with that black cover. Just having the opportunity to buy this book in 9.6 would be rare.