eBay is usually your first good bet. Otherwise, you could try and contact the publisher of the book to see if they have additional copies lying around. For example, I know for a fact that Grant Books (publishers of Stephen King's Dark Tower series in hardcover) usually has a board on their website that allows you to list particular copies that you are looking for or have available to sell to other people searching for books.
cough up the name of this book BC... I have my own "WHY is this out of print?!?!?!?!?" list. Included are
and
Originally posted by Mr Zero
cough up the name of this book BC... I have my own "WHY is this out of print?!?!?!?!?" list. Included areand
Yeah, Cat. We can't really help you out any more without a book name.