What to spend 300 platinum on?

So, I bought the Piercing Step pinnacle pack because 50% off for it seems like a damn good deal, and now my excalibur looks kinda neat. Anyway, Im pretty new to the game (my excalibur is rank 14 and im just about to get m2) and was wondering what the smartest things to spend this 300 on would be? (306 in total, if that actually matters)