Spell Costs Increased?

[incognito]

I'm trying to figure out why the spell costs for murdering winter, flames from the sky, and some other long range bombardment spells increased so substantially from DomII. In my experience, these spells were already expensive and tended to be only moderately effective versus many troop types. Moreover, with early age races having very high hp on their troops, the damage from these spells can seem even more inconsequential than normal. Is this a bug? Was the spell effectiveness increased? Given these cost increases, what long range bombardment spells have become people's favorites in practice?