A copy of Detective Comics #27, which marks the debut of Batman, sold at auction today for more than $1 million, barely breaking a record set just three days ago by Action Comics #1.

The Associated Press reports the Certified Guaranty Company-graded 8.0 issue, sold by Heritage Auction Galleries on behalf of an anonymous party, was purchased for $1,075,500. Earlier estimates had the May 1939 issue selling for $100,000. However, as CBGExtra notes, bids had already reached $400,000 by the time the auction opened.

Before this week, the record for the most expensive comic book was $317,000, set in 2009 by a copy of Action Comics #1.