First of all, it states quite clearly in the book and in the online guide FAQ:
What we've attempted to do is make a guide that is not only easy to use, but informative for the collector. Each title is listed with pertinent information as well as some notes of interest. The price values and scarcity ratings listed here are to be used just as a GUIDELINE, this is NOT "the Bible". Many titles listed here are more readily available (or scarcer) in some areas than they are in others, and most likely will be found for HIGHER prices on online auctions such as eBay. This listing represents the combined efforts of many of the hobby's top collectors and dealers.
BEFORE POSTING HERE please read our philosophy on rarity ratings and pricing, right here:
Things change, and as we do try to keep up with all 35,000+ listings in our database, it's impossible to stay on top of everything at all times, so we do hope that using our philosophy you can aid us in pointing out items that are clearly outdated. Please use this thread to do so!
Thanks as always for your support! The database gets better with every scrap of info we get and we really do appreciate it.