Rare Superman comic found in US house IT'S considered the Holy Grail of comic books: Action Comics No. 1 from 1938, featuring the debut of Superman. And Minnesota resident David Gonzales found one mixed in with old newspapers insulating a wall in a small town house he was renovating. He did some research that confirmed the comic was valuable but not as much as it could have been. Gonzales got into a heated discussion with a relative about its value, and the back cover got ripped. Because of the damage, New York-based online auctioneer ComicConnect.com has graded the book a 1.5 on a 10-point scale. By comparison, an Action Comics No. 1 graded a 9 recently fetched $US2.16 million ($A2.23 million). Bidding on Gonzales' find was up to $US127,000 as of Friday, and will close on June 11.