MINNEAPOLIS (AP) - It's considered the Holy Grail of comic books: Action Comics No. 1 from 1938, featuring the debut of Superman. And David Gonzales found one mixed in with old newspapers insulating a house he was renovating in a small town in Minnesota.

Gonzales did some research that confirmed the comic with a cover showing the Man of Steel holding a car over his head was valuable, though it's not worth as much as it could have been.

The book sat undisturbed in the ceiling of the house in Hoffman for over 70 years. But a few days after he found it, Gonzales said, he got into a heated discussion with his wife's aunt about its value, and she wanted a cut of the money. He said he also grew irritated because every time she would turn a page, crumbs of paper would fall out.

Finally he said, he grabbed it and tossed it aside, accidentally tearing the back cover.

"I don't care about the money," he recalled telling her. "I don't care. It's my comic book. I can burn it if I want to."

Gonzales said his wife's aunt backed down when his wife warned her he was serious.

Partly because of the damage and partly because the book shows the effects of its long service as insulation, New York-based online auctioneer ComicConnect.com said it's graded 1.5 on a 10-point scale. By comparison, an Action Comics No. 1 that was graded a 9 recently fetched $2.16 million.

"Valuable comic books so often have almost magical - and in many cases, ironic - back-stories like this," said Vincent Zurzolo, co-owner of ComicConnect.

Bidding on Gonzales' find was up to $137,000 as of Friday. Bidding will close June 11. Gonzales said he figures he'll get about half the sale price after the auction site and the Florida comic dealer he originally took the book to get their share.

Gonzales said he understands the ripped cover and other damage might have shaved $75,000 off the potential price. But he said that doesn't bother him.

"I'm not a hungry person about money," he said, adding that he'd rather work for it.

With a monkey.

Guy in Florida can make a market. That's worth a 50% cut if he can get a high sale price.

Try sticking something like that on ebay. Waste of time.

I would like someone to create a market for my penis.

I would like someone to create a market for my penis.

I would like someone to create a market for my penis.

Gonzalez was calm when he talked about the auction Wednesday night, and then he told ABCNews.com that he had found a second Action Comics issue featuring Superman while he was working on the house Tuesday. The second comic was also hidden in the walls of the house, he said.

RELATED: 1938 Superman Comic Worth More Than $100K Found Inside Walls of Old House

Gonzalez doesn't yet know whether it's worth as much as his first find, which sustained some damage when an eager relative handled it too roughly, ripping the back cover.

"We know it's a Superman issue, we just don't know what issue," Gonzalez, 35, said of the second comic. "I know it's the one [of Superman] fighting with the dinosaurs."

...

He said he doesn't plan a big spending spree. He plans to invest his winnings in his children's education and possibly buy another house to renovate. He also said he plans to donate $10,000 to St. Jude's Children's Research Hospital.

Gonzalez has been thinking about buying his dream car - a 1992 Chevrolet Camaro IROC - but he's not sure about that.

"I'll think about it," he said. "Man, my kids are going to need that money in the future."

It's conditionmust have been really bad.

His Action #1 only sold for $175,000? It's conditionmust have been really bad. According to the article the 50% turned into 10%.