So my best friends husband died 20 years ago and he left behind a big box of comic books.

[KY_EnviroGuy]

6. The Overstreet Comic Book Price Guide is the premier source....

The Overstreet Comic Book Price Guide

See: https://www.gemstonepub.com/en/

About them.....

Best known as the home of The Overstreet Comic Book Price Guide, Gemstone Publishing, a division of Geppi's Entertainment Publishing & Auctions, was formed by Diamond Comic Distributors President and Chief Executive Officer Stephen A. Geppi as a conduit for his efforts in preserving and promoting the history of the comics medium.

Gemstone's product line also includes recurring publications such as The Big Big Overstreet Comic Book Price Guide, Overstreet's Comic Book Marketplace Yearbook, The Official Price Guide to Pop Culture: 150 Years of Character Toys & Collectibles, and a variety of special editions such as The Overstreet Guide to Grading Comics, The Overstreet Guide to Collecting Comics, and The Overstreet Guide to Collecting Comic and Animation Art.

Past publications include such titles as The Overstreet Comic Book Grading Guide, Hake's Price Guide To Character Toys, The Official Price Guide to Disney Collectibles, The Official Price Guide to Mechanical Banks and The Overstreet Indian Arrowheads Identification and Price Guide, as well as periodicals including Comic Book Marketplace, The Overstreet Comics Price Review, Overstreet's Fan, The Overstreet Comic Book Monthly, and Overstreet's Gold and Silver Age Quarterly. Back issues of many of these titles are available for sale on the Gemstone website. Gemstone also published Disney comic books under license from 2003 through 2008.

Along with our sister company Diamond International Galleries, Gemstone also co-publishes Scoop, a free weekly e-newsletter which looks inside the world of pop culture with a focus on auctions, toys, comics, posters, art and anything and everything pop culture! The spotlight is on fun, while also offering informative insights into the beloved playthings of the past and how they have influenced our culture.

also sold on Amazon: https://www.amazon.com/Overstreet-Comic-Book-Price-Guide/dp/1603602526

My son, the sports and memorabilia nut, says if these are quite old and in good condition, it's definitely worth having them valuated. Some comics from the 30s and 40s have sold for millions.

This is an on-line pricing site you may want to investigate: https://comicspriceguide.com/

About them:

Now located in downtown Indianapolis, ComicsPriceGuide.com is comprised of a team of passionate comic book enthusiasts, who are just as passionate about technology. Started in 1995 as a tribute to the memory of Tim Beck, a close childhood friend of founder Bryan Neely, who unfortunately passed away from complications due to leukemia at the age of 25.

From the early days of their friendship, they were both focused on the world of comic reading and collecting. Their entire world revolved around this hobby. It didn't stop even while Bryan was going to college. At Ball State university, Bryan created the very first percursor of ComicsPriceGuide.com. Initially it was named MarvelWorld and featured only data and related information exclusively on Marvel Comics.
Fast-forward 18 years and ComicsPriceGuide.com has become the world's largest and most accurate online community for obtaining comic book value information. In addition to serving over 700,000 users value data, our message boards and blogs have become the go-to-source and authority for connecting comic book enthusiasts.

Our values remain simple, but our technology is not. Using a proprietary value algorithm, paired with dedicated comic enthusiasts, we are able to preserve real sales data to get up-to-the minute comic book value information.

My son also mentioned most all cities have one or more comic book/gaming/sports card shops (Louisville has several) and you may want to call around to those places to see if they offer professional help with valuations.

Best of luck!.......