It makes Iron Man's first appearance the second-most valuable Silver Age comic after a copy of Amazing Fantasy No. 15, featuring Spider-Man's first appearance, which sold for $1.1 million last year.

The sale shows the impact of Robert Downey Jr.'s fan-favorite portrayal of the armored avenger on the collectibles market. Iron Man’s first appearance is now more valuable than such important silver age Marvel milestones as the Fantastic Four No. 1, Avengers No. 1, the first appearance of the Hulk in X-Men No. 1 and the return of Captain America in Avengers No. 4.

The Tales of Suspense sale follows a run of record prices for vintage Avengers-related comics in 2011 and 2012. In February, a copy of the first appearance of Thor in Journey Into Mystery No. 83 sold for $222,200, more than doubling the previous high price.

A copy of Captain America No. 1 from December 1941 sold for a record $343,000 in August. The first modern appearance of Captain America came in Avengers No. 4. The record price for that comic? A relatively paltry $91,500 in February 2011.

Topping it off, a CGC 9.6 copy of Avengers No. 1 sold in November for a record $250,000, zooming past the previous high of $100,000.

Only The Incredible Hulk No. 1 has failed to set a record price in 2011 or 2012, and probably the only thing holding it back is its rarity. The Hulk debuted in March 1962, behind the Fantastic Four but a few months ahead of Spider-Man and Thor. The original series only lasted six issues (the character was revived 18 months later in Tales to Astonish), and pristine copies of No. 1 are hard to come by. The last record sale occurred at Heritage Auctions in 2009, when a copy changed hands for $125,000.

Looking to assemble your own collection of vintage Avengers comics? Be prepared to fork over at least a cool $1.3 million for a set -- a price that sure to rise with the movie's success.