A copy of Superman #1 (1939) has a $262,905 opening bid in a sale of comic books at Heritage Auctions.
This was the first official Superman release following the extraordinarily successful debut of the character in Action Comics #1 a year before.
This unrestored example has been graded VG+ 4.5 by CGC.
Heritage explains: "Unrestored copies of this major key are very difficult to come by.
"We have never offered an unrestored copy graded better than 5.0, and the last time we saw one even in that grade was way back in 2007."
The record for the issue is $299,000, set for a 4.0-graded specimen earlier in the year. This lot could well set a new high mark.
Bidding on Steve Ditko's original cover art for Amazing Spider-Man #27 (1965) stands at $191,200.
Titled Bring Back my Goblin to Me!, the piece features Spider-Man and his arch enemy the Green Goblin.
Ditko co-created Spider-Man along with Stan Lee in 1962.
The auction houses comments: "To state that... Ditko original art pages such as this are highly sought by collectors is of course a major understatement, and few can match this example's condition and eye-appeal!"
The November 17-19 sale will also feature a collection of underground comic art, led by Jack Davis' original artwork for Casey at the Bat!
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