It's worth every penny. Beware of laggy spellcasting enemies in PvP, though. High ping sorcerers are the true evil of that game. Lag and the likes aside, it is amazingly fun and decently challenging. Easily one of the best RPG's out there today, in my opinion.
It's not really as challenging as people make it out to be (unless you do SL1 runs) but a damn good RPG. The PvP ain't so hot though imo