Earhart Souvenir: A souvenir envelope autographed by Amelia Earhart that was intended to be on her ill-fated 1937 round-the-world-flight will be auctioned by Christie’s New York on Sept. 25. Estimated price: $20,000 to $30,000. Some 7,500 envelopes were to accompany the aviator, but at the last moment a friend removed one as a practical joke. His intent was to wave it at Earhart when she returned and exclaim that the mail had arrived before she did. Instead, only this autographed souvenir survived.