Though this one wasn't sold in the best condition, it went for a decent price because the book itself — one of the first to feature less-than-perfect

protagonists — is considered one of the "most important comics of all time."

This comic book's starting price on eBay was just $14.99.

This book details how the Avengers formed; it's a must-have for any Marvel fan, but it can earn you big bucks if you choose to sell.

The Flash made his first appearance in this 60-year-old book.

It's no surprise that the comic book featuring Spider-Man's first appearance is one of the top-selling issues online.

This D.C. comic book, published in 1941, went for a lot even though its pages were "cream to off-white"-colored (meaning they weren't in top condition).

The second comic book in the Superman saga sold for ten cents back in 1939, meaning it's now worth nearly 120,000 times its original value.

Did you know one of your favorite TV shows was inspired by a comic book? An issue of this one (in pristine condition) sold well this September.

This 1962 Marvel comic book marked the very first appearance of everyone's favorite giant green monster.

According to this book's listing, it's particularly unique because it predates Captain Marvel's first official issue in Captain Marvel Adventures #1.