Comic book price guides are typically published on a monthly, quarterly, or yearly basis and provide comprehensive information about the fluctuations in the resale value of comics over a specific duration. These guides play a crucial role for collectors who intend to sell their collection or require an estimate of their collection's value for insurance purposes.

Each collector will have his or her own preference regarding which authority to follow, but popular and respected guides have included The Official Overstreet Comic Book Price Guide, Comics Buyer's Guide magazine, Wizard Magazine, the Comics Buyer's Guide Standard Catalog of Comic Books, and Human Computing’s ComicBase, an inventory/databasing software program.  Popular online price guides include comicbookrealm.com (free), ComicsPriceGuide.com (free and paid services), RarityGuide (free and paid), and GPAnalysis.com specifically for CGC (certified) Comics (paid).  Both online and print price guides can exhibit variations, leading collectors to rely on a blend of multiple sources to derive a precise estimated value. A common practice involves cross-referencing information from different guides. Additionally, checking completed auctions on platforms like eBay and Heritage Auctions proves to be highly beneficial in gauging accurate values for comic books.

While numerous price guides may emerge and fade over time, enduring publications like Overstreet (with a history spanning over 35 years) or more recent ones like the Standard Catalog of Comic Books have become integral components of comic collection history. These guides hold a strong appeal for collectors and enthusiasts, serving as valuable resources for a wide range of information. They offer insights into storylines, writers, artists, and even the original cover price of a comic.

Online platforms like the Grand Comics Database and comicbookrealm.com provide users with rapid access to character appearances and deaths. Additionally, the Big Comic Book Database merges a searchable database featuring character and creator details per issue with a linked price guide, offering a comprehensive resource for enthusiasts.

The advent of certification enabled increased liquidity of comic books by removing disputes over grading and by disclosing restoration, and accelerated sales of comic books through online auction sites such as eBay or Heritage Auction Galleries. Certification holds significance for certain comic price guide providers as it imparts a sense of assurance regarding the precise grade of the comic book being offered for sale. Nonetheless, since certified books are graded by multiple individuals, the reliability of these services is not universally accepted. Online platforms offer individual as well as aggregated records of certified comic book sales, aiding collectors in accessing this information.

History 
From the early 1960s onward, the community of comic collectors, who frequently engaged in trading and selling among themselves, experienced a notable growth. This expansion was accompanied by an increase in the number of comics dealers operating within the industry. In 1965, Michael Cohen and Tom Horsky published what is considered the first comics price guide, the one-shot digest The Argosy Price Guide (specifically for Hollywood, California's, Argosy Book Shop).

Comic back-issue prices had stabilized by the end of the 1960s.  In 1970, Jerry Bails, who had recently published the Collector’s Guide to the First Heroic Age, was considering creating a comic book price guide. He was contacted by Bob Overstreet, who was doing the same thing. Bails' extensive notes, supplemented by Overstreet's study of dealer listings, "became a backbone to the Overstreet Comic Book Price Guide." Overstreet's guide instantly became an invaluable resource tool for comic book collectors.

The initial editions of the Overstreet guide did not include the category of underground comix in its listings. This gap was addressed by Jay Kennedy in 1982 with the publication of The Official Underground And Newave Comix Price Guide. Though now out of print, this guide remains a valuable resource for information about artists and publishers within the underground comix genre. In 2006, Dan Fogel, who was an advisor and contributor to the Overstreet guide, published Fogel's Underground Comix Price Guide. In 2010, a supplementary magazine was introduced, encompassing minicomics and British undergrounds alongside the latest pricing data.

The emergence of online auction platforms like eBay led to significant declines in the sales of traditional price guides. This was attributed to the fact that the price listings in these guides did not accurately reflect the actual sale prices of comics. Subsequently, publications such as Comics Buyer's Guide magazine and the CBG Standard Catalog of Comic Books began reporting genuine completed auction results from eBay. These reports span longer periods than what eBay's online results typically cover. The 2005 edition of the Standard Catalog is extensive, spanning 1,624 pages and reporting results dating back to 2002. Currently, the online price guide for slabbed comics is GPAnalysis, which aggregates data from verified sales by several pre-approved sellers and auction houses.

To ensure independent evaluation and impartial certification, established third-party companies like Certified Guaranty Company (CGC) or Comic Book Certification Service (CBCS) offer grading services for comics. These companies allow comic books to be submitted for comprehensive assessment, including grading, restoration checks, and encapsulation within tamper-evident protective holders.

Comic book grading scale
In the realm of comic book grading, disagreements between dealers and graders regarding certain classification assessments are not uncommon. The process of grading comics can be subjective, even though the industry has established fundamental standards. A numeric system is employed alongside a titled grading system, with both ranging from 0.5 (Poor) to 10.0 (Mint or "Gem Mint"). While some collectors and companies solely utilize numeric grading or terminology, mixed grades with titles like Very Good/Fine (5.0) adhere to the lower grade being stated first, followed by the higher grade.

Furthermore, within the established grades, descriptive notes might be included. This is because comics assigned the same technical grade can have differing reasons for receiving that grade. Moreover, individual collectors often possess their own preferences and biases regarding which imperfections they find more tolerable than others.

Terminology
 Title is the name of a comic book series. For example, Action Comics is a title. Within this title, there have been over 1,000 issues.
 Issue is a single installment of a title, usually with its own number. Examples are Action Comics #23 or The Amazing Spider-Man #42.  A volume number may also be included, such as Punisher Vol. 1 #23.
 Grading is the process of evaluating the condition and consequent value of a comic book. A detailed explanation of how to determine a comic book’s condition based on the established grades is generally included in a comic book pricing guide.  A copy that falls between grades may be noted with a  or a  symbol. These terms are as follows:

Notable price guides

Printed guides 
 The Official Overstreet Comic Book Price Guide
 Comics Buyer's Guide
 Comics Values Monthly (Defunct)
 Standard Catalog of Comic Books
 Wizard: The Guide to Comics (Defunct)
 British Comics, Story Papers, Picture Libraries, Girls Papers, American Reprints, Facsmilies, Giveaways Price Guide (1982)

Online guides 
 ComicBase
 Covrprice
 Zap-Kapow Comics
 GP Analysis for CGC-graded Comics
 Sell My Comic Books
 Nostomania
 Quality Comix

See also
 Direct market
 Comic book collecting

References 

Comic book collecting
Online comic databases