World's most expensive book up for grabs

If you like this picture of snowy owls and have a spare £4 to £6 million floating around, you might want make a bid for Audubon's book Birds of America when it goes to auction on 7 December at Sothebys, London.
Reputedly the most expensive book in the world to be part of a commercial print run, the book was written and illustrated by John James Audubon (1785-1851), a renowned ornithologist, naturalist and painter. A copy of the same book was auctioned 10 years ago for a world record price of $8.8 million. Only 119 complete copies are known to exist today, 108 of them in museums and libraries.
If this doesn't quite suit your budget, why not try and get hold of a first-edition copy of Darwin's On the Origin of Species: yours for somewhere between £35,000 to £60,000. Or, if your tastes are a little more expensive, get in touch with Bill Gates. In 2007, Gates paid a cool $30.8 million for Leonardo da Vinci's Codex Leicester - but then, that was da Vinci's personal notebook.