On Thursday, February 18, Heritage Auctions auctioned off a Certified Guaranty Company (CGC) graded 9.4 copy of "Amazing Fantasy" #15 at their Comics and Comic Art Signature sale in Dallas. As one of the highest-graded copies of Spider-Man's first appearance ever to be sold at public auction, it was expected to fetch a high price. In fact, it set a record, selling for $454,100. That's the most ever paid for a Spider-Man comic at public auction.

To commemorate the sale, CBR compared it to the current record for a copy of "Amazing Fantasy" #15 as well as other notable comic books. Below is a list of the ten most expensive comic book sales of all-time, on a per-title basis. Instead of listing the biggest sales ever, we'll stick to the most expensive copy of each title rather than listing every notable sale of "Action Comics" #1, for example.

10) "Incredible Hulk" #1, CGC 9.2 -- $326,000

Perhaps the hottest collectible comic book in recent years has been the first appearance of the Incredible Hulk in this 1962 comic book by Stan Lee and Jack Kirby. There is only one copy known to exist that is graded better than the 9.2 that sold in August of 2014. That sale followed another 9.2 copy selling in June for $320,000. Yes, twice in a matter of months people paid over $300,000 for the Hulk's first appearance! This big leap in price for the comic (the $326,000 copy sold for less than half that five years earlier) has led to a multitude of other copies of this comic going to market, with prices rising for copies in all sorts of conditions.

9) "Captain America Comics" #1, CGC 9.2 -- $343,057

If people think that Nick Spencer's "Captain America" is too political, you would think that they'd be shocked by the first issue of Joe Simon and Jack Kirby's "Captain America Comics," which features their creation punching the leader of a country that the United States was not even at war with at the time. The comic became a sensation, leading to death threats against the two young Jewish comic creators. This copy sold in 2011.

8) "Marvel Comics" #1, CGC 9.0 -- $350,000

The advent of the comic book grading industry at the turn of the 21st Century is what has really driven the recent explosion in the comic book auction market. Thus, it is important to note that "Marvel Comics" #1 (the first comic book published by the comic company that would eventually become Marvel Comics, and also the first appearances of both Namor and the original Human Torch) is only this low on the list because the highest graded copy sold is "just" a 9.0. The typical rule of thumb is that prices double for every 0.2 after a 9.0. When you add in the fact that this copy sold in 2003, a higher graded copy of this comic will very likely eventually end up at the highest end of this list (similarly, "All-American Comics" #16, the first appearance of Green Lantern, isn't even on the top 10 list, but when the next 9.0 or better copy goes on the market, it almost assuredly will end up very high). While I've seen some references to a copy of this book selling for $367,000, no reliable sources have demonstrated such a sale actually occurred.

7) "Tales of Suspense" #39, CGC 9.6 -- $375,000

Speaking of grading, Jack Kirby and Stan Lee's "Tales of Suspense" #39, the first appearance of Iron Man, is a major example of the effects of a high grade on major collectibles. This 2012 sale was likely also buoyed by the attention that Iron Man has been given as a movie character in the years since the first Robert Downey Jr. film was released.

6) "Flash Comics" #1, CGC 9.6 -- $450,000

Now would be a good time to discuss Edgar Church. Church was a commercial artist and avid collector of pulp magazines and comic books. Due to where he lived in Colorado, his basement (where he kept his books) worked as a sort of humidor, keeping the books in stunning condition. Most of the best quality Golden Age comics in the world come from his collection (most of which were purchased by Chuck Rozanski of Mile High Comics, leading to books from this collection being referred to as either being from the "Mile High Collection" or the "Church Collection." This copy of "Flash Comics" #1, the first appearance of the Golden Age Flash and Hawkman, is from this collection. It sold in 2010 for what was, at the time, the second-largest amount of any comic book ever (of course, to show just how much in flux the industry was at the time, the highest sale at the time was a month earlier and two different highest sales occurred later that same year).

5) "X-Men" #1, CGC 9.8 -- $492,937.50

The effects of the slight grade increase is evident in this 2012 sale of the first issue of Stan Lee and Jack Kirby's "X-Men" series, as the previous copy sold was a 9.6 that sold for a little less than half the price of this copy, which is the highest graded book of any of the comics on this top ten list.

4) "Batman" #1, CGC 9.2 -- $567,625.00

An energetic bidding war in 2013 led to this classic comic, the first issue of Batman's ongoing series and the first appearance of both the Joker and Catwoman, becoming one of the very few comic books in history to ever crack the $500,000 barrier.

3) "Detective Comics" #27, CGC 8.0 -- $1,075,000

Never has the vagaries of grading when it comes to the sales of valuable comic book collectibles been quite so acute as the fact that "Detective Comics" #27, containing the first appearance of, you know, Batman, is only the third-ranked book on this list, after initially setting the record for the most expensive comic book of all-time when it sold in late 2010. This is because no one has sold a copy of "Detective Comics" #27 above an 8.0 in the modern era. The Chuch Collection copy is graded at an 8.5 and it hasn't been on the market since 1994 (when it sold for $125,000!). There are a handful of 9.0 copies and above out there, and if they ever went to market they would sell for a lot more than $1,075,000. There is a good case to be made that a theoretical 9.2 "Detective Comics" #27 is literally the most valuable comic book in existence.

2) "Amazing Fantasy" #15, CGC 9.6 -- $1,100,000

We can talk about the relative "value" about comics until the cows come home, but at the end of the day, when these things go to auction, you never know just how much people are going to bid, and sometimes the results will surprise you, like this copy of "Amazing Fantasy" #15 by Steve Ditko and Stan Lee, the first appearance of Spider-Man, which sold for over a million dollars in 2011. Experts certainly were expecting a very high total, but considering that the record for a Silver Age comic book at the time was under $300,000, this comic going for over a million was quite the shocker.

1) "Action Comics" #1, CGC 9.0 -- $3,207,852

Seen by many as the "holy grail" of comic book collectibles (although, as noted earlier, a good case could be made that "Detective Comics" #27 is actually the "true" holy grail of comic book collectibles), if you ranked the biggest individual sales of comic books, sales of "Action Comics" #1, featuring the debut of Jerry Siegel and Joe Shuster's historic Superman, would take up most of the spots on such a top ten list, with an astonishing four different copies having sold for a million dollars or more, with this 9.0 CGC ranking (one of only two officially graded 9.0 copies in the world) selling on eBay in 2014 for over three million dollars (after the other official 9.0 copy sold for $2,161,000.00 three years earlier). Note that there is a Church collection copy of this book, as well. The owner won't get it graded, but it is anecdotally graded at a 9.2.