A rare copy of John James Audubon's 'Birds of America' was sold for 7.3 million UK pound in a printed book auction by Sotheby's London.
I am not sure which copy or volume was the one that was sold for that amount, but it makes you think, its great to know someone out there really appreciates bird books out there !
Read: Bird Book sets auction record
Read: One of his book made available online (Birds of America. Vol III , 1841)