Hi Ranzan,

This is only a white mage perspective, but it has been my preference to have that Piety to have around 4500+ MP. It helps enough with the passive MP regeneration that you should be able to breathe between Shroud of Saints without relying on Mage's Ballad.

So a Vortex Ring of Healing for instance that has no Piety is less appealing to me than an i90 healing ring with Piety. BUT if you happen to have i70 / i80 / i90 gear set that both can use, certainly share them until you have more options.