Everquest RPG Spells/Mana question

[Voadam]

Is there a pattern or formula to the mana costs of spells in the everquest rpg? In flipping through the spells I noticed that while a spell would be different levels for different classes, it would have the same mana cost.

 

[Magius del Cotto]

(This should be in the D20 system games forum, just so you know...)
At this point, as far as I know, there is no known rhyme or reason for them assigning the MP cost for the spells, other than that's basically the costs that are in the online game. Of course, they may have released the formula, but I doubt it...
Anyone else know more than I?