What are good resources for my players to buy if they want to get more involved in the world?
The Players' Guide is obvious. You get the rules without all the boardgamey stuff. Great for a player who wants to do some reading and prep work at home. But other than that?
The Players' Vault not. It contains the boardgamey stuff from the basic set. It's cool to have, but it's shared stuff, likely to get mixed up if somebody brings their own. Maybe it'd work if every player has his own vault, but that's not likely to happen. In any case, I doubt it contains much world background, and that's what we really need.
Adventurer's Toolkit: same story. Useful to have once, but I don't need two trollslayers or 2 wardancers in my group.
Really, the interesting rules and background info are in the Tome of Mysteries, Tome of Blessings, and in the Winds of Magic and (presumably) Paths of Faith books. But the first two are only available as part of the Core Set, aren't they? I believe parts of them may also be in the GM's Guide, but that sounds like the wrong book to recommend to players. Winds of Magic and Paths of Faith also contain a lot of information for the GM, not to mention cards and other stuff that players don't need individually.
So I'm kind of wondering: am I missing something? Is this background information and rules on magic use not meant for players? That'd be silly. I want to encourage my players to read more background stuff, to get more involved in the world. I'd like them to be able to buy the books separately. But they can't. Can they?
(Originally I typed a lot more background here, but my browser threw it away. I might type it up again if anyone wants to know more about my group.)