Batman Debut Comic from 1939 Sells for $850k

Batman was first revealed in a comic book way back in 1939, and though kids could have bought it then for 10 cents ... a collector just paid $849,999.90 more to get his hands on one.

Detective Comics No. 27 is the vintage comic in which the Caped Crusader makes his first appearance, and there are fewer than 70 copies still remaining in the world ... according to online auction house ComicConnect.

One of those copies just sold for a whopping $850k, making it the second-highest sale price ever for that particular issue ... and one of the top comic book sales of all time.

Vincent Zurzolo -- co-owner of ComicConnect, which managed the sale -- says the comic probably would have gone for even more if it was in better condition, but it's only a 6 out of 10 on the CGC grading scale.

By contrast, another copy of No. 27 that was graded an 8 sold for a staggering $1,075,500 in 2010 ... setting the record for the Batman comic.

Zurzolo says the recent $850k sale reflects how the collectibles market is booming right now. As we've reported ... that's been evidenced by a Mike Trout rookie card netting a stunning $3.9 MILLION in August, and a LeBron James rookie card fetching $1.8 mil in July.

As for comic books ... Superman still reigns supreme. A copy of the 1938 edition of Action Comics No. 1 where the superhero debuted sold for $1.5 million, smashing all previous records.