Don't buy it until they do something about endgame.

In terms of PvE, you have to spam dungeons until you're geared enough to tackle hardmodes - which would be fine if they hadn't made this harder for no apparent reason. Unless you're a lancer it takes a stupid amount of time to find a group, whether you use matchmaking or wait to find a lancer in chat. Dungeons also have lockout cooldowns to stop you from doing them back to back (as if there was something else to do).

PvP is a bit dumb, with no reward and the chance of losing crystals (that can cost up to 200g each) anytime you try it. Deathmatches with other guilds are about as fun as it gets, and require a lot of effort and planning.

I'm pretty sure they're going to release new content right before the free month ends for everyone (end of may) to push people to resubscribe, but if they don't I wouldn't bother playing this. They don't seem to be doing much for the game's success.