It really depends on what it is. If it's something I love, it depends on what I can afford. I paid $500 for a first edition of The Hitchhiker's Guide with the Capricorn 1 ad on the back. And I paid quite a bit for an American first edition copy of The Hobbit that I used in place of a ring to propose to my now wife. But most of my books are pretty cheap.
I did manage to find a first print/edition copy of The Shining for $1 at a library sale years ago...that was a cool find.
It really depends on what it is. If it's something I love, it depends on what I can afford. I paid $500 for a first edition of The Hitchhiker's Guide with the Capricorn 1 ad on the back. And I paid quite a bit for an American first edition copy of The Hobbit that I used in place of a ring to propose to my now wife. But most of my books are pretty cheap.
I did manage to find a first print/edition copy of The Shining for $1 at a library sale years ago...that was a cool find.