Call of Cthulhu Humble Bundle
Humble Bundle is hosting Chaosium right now.
$25 gets you twenty-five books, $15 ten, $5 four. Incredible value since I think I've paid $50 for hardcover versions of at least a couple of these.
Bring a taste of terror to your game nights with this bundle from Chaosium, complete with everything you need to run the dreaded (yet beloved) Call of Cthulhu RPG system! On top of the Call of Cthulhu Starter Set, you’ll get the Investigator Handbook, replete with expanded rules for creating player characters, as well as the Keeper Rulebook, brimming with all the information you need to keep things orderly as your table descends into madness. You’ll also get tons of adventures, including some aimed at first-time game masters, as well as entire campaigns! Pay what you want for over 25 books and game aids for this seminal RPG and help support the World Wildlife Fund with your purchase!