I've been reading up on the LCG and thinking about getting it. It says it's good for 1-2 players, but the expansion packs say they're good for 1-4. Can anyone explain how this works to me so I'll know what to expect before buying a bunch of stuff I can't use?

With 1 core set you have enough cards for 2 players to start deckbuilding. The rules support up to 4 players and the expansions take into account that you might have access to more than 1 core set.

In general I´d say each serious deckbuilding player should have his own core set (+maybe expansions). This makes it much easier for the players to fiddle with their builds. Though you could also use a site like www.cardgamedb.com to help manage it.

Also I think this is posted in the wrong section. This section is for discussing the print on demand expansions for the game