Lowering energy consumption on lower level spells or possible spell haste stat

[Chupon]

I think a good way to improve casters mana efficiency or make them more viable at lower levels would be to gradually decrease the energy needed to cast older spells. Lets say you are a mage or druid around level 10-15 range. Instead of casting 1 magic missile or frost jet/round maybe have the energy needed to cast the spell go down with level. That way for certain spells you would get maybe 3 magic missles / round at level 15, 2 at level 10 etc. This might not work well with multicast spells such as mete or magma blast but i think it would be nice to still use lower level spells throughout the progression of the game to save mana. Even having the spell difficulty vs current level of spellcasting come into play. It might make mages. priests, and
non-melee statted druids able to level up at a reasonable pace prior to level 30+. A new spell haste type of system such as a new flag to put on weapons and armor might also be an alternative.

-Chupon