The most recent bid for CGC 6.0 copy of Action Comics #1, currently being auctioned at ComicConnect.com, has reached over $275,000, with eleven days still left before the close of the auction.  42 bids have been placed on the book to date. 

 

Only about 100 copies of Action Comics #1, the first appearance of Superman and the first superhero comic, are known to exist.  This copy is being sold on behalf of an anonymous seller who bought the comic in 1950 (it was published in 1938).