Basically what I have in mind is a series of purchasable buffs in the pay vault that when bought are applied to all players for a set duration, and these buffs are called "Graces"!

Graces are ideally purchasable only once per 24 hours, once bought, the respective grace will apply a stackable, global buff to all players for a duration of 24 hours before dissipating. The percentage increases given by the grace system is up for debate as well as it's cost, but I believe that it would be nice to see some cooperative pay vault options!
I figured in one of the major cities, there could be a priest you can speak to in order to observe the total of the graces stat buffs, as they would be able to be stacked for each purchase player to player.
Function and Layout
Idol of Riches- All players in game gain a (X)% increase in their gold drops for 24 hours.
Idol of Mastery- All players in game gain a (X)% increase in their XP yield for 24 hours.
These are currently the only two graces I have in mind as of right now, so please tell me what you think of the idea..!