The 10 Most Expensive Books in the World

It could be a record-breaking afternoon in the book world. Today, Christie’s New York will auction off a copy of John James Audubon’s Birds of America, which already holds the title of most valuable printed book in the world, having sold for about $11.5 million in 2010. In fact, according to The Economist , a true list of the ten most valuable single books ever sold would have to include five copi