$1.5 Million !

 https://www.hollywoodreporter.com/heat-vision/first-batman-comic-sells-for-record-1-5-million

This was the most expensive comic ever sold by Heritage Auctions

 

Artist Bob Kane and writer Bill Finger's story "The Case of the Chemical Syndicate," published in Detective Comics No. 27, introduced the world to The Dark Knight.

The Detective Comics sale came during the first session of Heritage Auction’s four-day Comics & Comic Art event, which runs through Nov. 22 and features the so-called “Alfred Pennyworth Collection”, a Batman-centric collection from Randy Lawrence; his Batman No. 2, from 1940, sold for $63,000 during the same session.