$30.8 million: Also known as the Codex Hammer, it is a collection of scientific writings by Leonardo da Vinci. It was purchased by Bill Gates in 1994.
$14.2 million: Printed in 1640, it is the first book printed in what is now the United States. Only 11 copies of this book exist, and in 2013, one was sold at auction for the mentioned price.
$11.5 million: A book by John James Audubon, it is a collection of illustrations of American birds. Only 119 copies are known to exist, and in 2010, a copy was sold for the mentioned price.
This edition of Geoffrey Chaucer's famous work was published by William Caxton in 1477. It is one of the earliest printed books in English and is highly valuable to collectors.
Published in 1623, it is the first collected edition of William Shakespeare's plays. It contains 36 of his works and is highly sought after by collectors.
Created in the 12th century, this illuminated manuscript is one of the most significant examples of Romanesque book art. It is currently housed in the Herzog August Library in Germany.
Written and illustrated by J.K. Rowling, the author of the Harry Potter series, only seven handmade copies of this book exist. In 2007, one of them was sold at auction for the mentioned price.
: This is a different copy of the First Folio mentioned earlier, which was sold in 2001 for the mentioned price. It is one of the most important books in English literature.
Also known as the 42-line Bible, it is the first major book printed using movable type in the 15th century by Johannes Gutenberg. Only 49 copies are known to exist, and it is considered one of the most important books in the history of printing.