Instruct: Classify Amazon reviews into positive or negative sentiment
Query: OK, but.....

Some useful info but it's absurd that this is a "2000 edition" and covers books up to about 1993! What did he do when he updated this book, close his door and stay inside from 1993 to 1999 writing this book, ignoring any books written after 1993? Weird.What boggles my mind is how few books there are on pricing and grading first edition books, and the ones that do exist are not very good, including Aherns. Why can't someone come out with a decent one like they do for comic books (Overstreet, etc)?