There are 10 Volumes each of 4 issues and a best of issue for Volume 1.  The First two volumes seem to sell fairly well but the later ones are usually pretty cheap.

Mars wrote:There are 10 Volumes each of 4 issues and a best of issue for Volume 1.  The First two volumes seem to sell fairly well but the later ones are usually pretty cheap.

ADQ value, while never that great, is pretty easily divided with a visual clue: the early issues were digest-sized, had a higher quality of article (generally speaking), and tend to fetch a higher price; the later issues were magazine-sized, had goofier articles (the whole system was goofy by that point), and usually fetch lower prices.