Chances are, your uncle probably has a few boxes of old comic books stashed in his attic or garage, in bins that someone might have labeled as “junk.” That’s just not the case after watching the comic book collectibles market soar over the past two decades.

People have sold their nostalgic and high-graded comic books for well over a million dollars, so it’s a better time than ever to scrummage through your uncle’s “junk” boxes and get those copies graded! Below are the top three highest selling comic books, breaking records left and right.

The “Detective Comics” #27 broke the most expensive comic book record in late 2010. Not only does this comic book feature the debut appearance of Batman, but interestingly, there’s been no record of anyone selling a copy of “Detective Comics” #27 above an 8.0 grade in the last twenty-odd years.

The last sale of this comic book was in 1994 when the Church Collection-graded 8.5 copy sold for a whopping $125,000. 9.0 copies of this comic book are incredibly rare, but they’re out there alright, and they would generate more than $1,075,000 if sold today. CBR pointed out that if there were a “Detective Comics” copy graded at 9.2, this would be the most valuable comic book ever to exist.

Sometimes, it can be difficult to decide how much a comic is worth because several underlying factors are at play. This is why auctions are a great place to start and get a feel for the prices people are willing to pay for a comic book from their childhood. “Amazing Fantasy” #15 by Steve Ditko and Stan Lee introduced the world to Spider-Man, so it goes without saying that this book is one of the priciest on the market.

At an auction in 2011, “Amazing Fantasy” #15 sold for just over a million bucks. At the time, Silver Age come books would usually sell for roughly $300,000, so the record high price of over a million dollars was a huge surprise to all.

Last but certainly not least is the “holy grail” of comic book collectibles, according to CBR. Enter Superman, thanks to Jerry Siegel and Joe Shuster’s iconic “Action Comics” #1. Impressively, this book has four different copies that make up for some of the largest comic book sales ever. Each copy sold for a million dollars or more.

In 2011, a 9.0 graded copy of “Action Comics” #1 sold for $2,161,000, but that’s not all. In 2014, someone sold their 9.0 graded copy on eBay and brought home a record-high of $3 million.