A stash of classic comic books -- the kind that most kids tossed in the back of their closets -- was sold for $3.5 million at an auction Wednesday in New York, according to USA Today. The top price of about $523,000 was paid for a copy of Detective Comics No. 27, which sold for 10 cents in 1939 and features the debut of Batman. according to Heritage Auctions, Also sold was Action Comics No. 1, which featured the debut of Superman; it sold for about $300,000.

The comics were found in a basement closet by a California man who was cleaning out his great aunt's Martinsville, Va., home a few months after her death, the newspaper said. But it took a while before he realized their tremendous value.

“While a relatively small collection of little more than 300 comic books, The Billy Wright Collection represents not only five of the top six comics in the business, but also 45 of the top 100 comics overall, all unrestored.” Lon Allen, Managing Director of Comics Auctions at Heritage, said on the company website.

If you couldn't make the New York auction, don't worry. You can see some of these historic comics right here in Baltimore, at Geppi's Entertainment Museum. And it won't cost millions.