The definitive price guide for comic books, as of 2105, is “The Overstreet Comic Book Price Guide,” originally started by Robert M. Overstreet. In 2015, Gemstone Publishing released the 45th edition.
“The Overstreet Comic Book Price Guide” is so widely accepted by collectors that comic book stores reference it for pricing and acquiring stock. Prices in stores and at conventions often state “above guide” or “below guide,” directly referencing “Overstreet” prices. For example, at MetropolisComics.com, the Hot Deals Discount Section indicates the comics listed are “below guide” prices. Customers of Amazon.com give “The Overstreet Comic Book Price Guide Volume 45” 4.9 out of five stars.