Most Expensive Spells in the Game

[WarpathEQ]

If you notice the spell costs are pretty directly correlated to how valuable the spell is to that class maximizing their potential, and how effective the class is at farming. AKA the most expensive spells are expensive because they earn players the most money.

For example I've probably made about a 2500% return on buying Torpor for my shaman and subsequently farming stuff that I couldnt without Torpor.