Nicolas Cage better get his eBay account ready for Aug. 14 and make sure he’s got an extra few million sitting in the bank. That’s the day that a rare, near-mint copy of Action Comics No. 1 with Superman’s first ever appearance hits the auction site.

The Certified Guaranteed Company announced on Wednesday that it has graded a copy of the 1938 issue with a 9.0 out of 10. It is believed that there are only 40 to 50 original copies of the book in existence. Since DC Comics didn’t quite know how popular Superman would become, only 200,000 were printed in June 1938.

The book is being sold by Darren Adams, a collector. He will begin the unreserved auction on eBay on Aug. 14 and it will be open for just 10 days.

CGC said that it has only graded one other copy of Action Comics No. 1 a 9.0. That copy sold for $2.16 million on ComicConnect.com in 2011. It is expected that the new auction will surpass that number.

“This is an extraordinary opportunity to acquire the most valuable comic book in existence and we look forward to sharing a piece of pop culture history with the global eBay community,” Gene Cook, General Manager of Emerging Verticals for eBay Marketplaces, said in a statement.

CGC and eBay have launched a dedicated page for the comic book. In addition, CGC posted a digital copy of the book, which you can examine if you plan on spending a few million. Part of the proceeds from the sale will go to the Christopher & Dana Reeve Foundation, named for the late Christopher Reeve, who played Superman in the 1978 movie.

image of Henry Cavill courtesy of INFphoto.com