As it is currently written, a Greater Crystal of Expertise (weapon) will not help me use this sweet longsword I just found because it only works on exotic weapons. Similarly, the greater armor version only helps me wear full plate, not this breastplate. Make them work as the lower level crystals plus another ability.

The crystal of weapon alignment seems undercosted for +2d6 damage to a broad swath of enemies. Maybe up the price by 1K or so and only apply the damage to people of opposite alignment as the crystal, so a good crystal only hurts evil things more, not neutral as well.