HEL Pit Fiend said:
SIGH...
battlehammer, your homework is to try the same for (enhanced vs double empowered):
1. cone of cold (15d6)
2. chain lightning (20d6)
you will find Empower wins, Empower always wins in the end
YOUR homework is to re-read my post.
I said the same thing as James McMurray. Granted he said it better

, but the point was that if you get all feats down to +1 spell slots, empower becomes LESS powerful, enhance and intensify become more powerful. Your equations had only one feat for the feats you do not like, yet used your favorite feat twice. Of course you will get better results that way. Not to mention that you forgot to round down, so empower still loses. (17.5 = 17)
As to the need to take multiple feats being exspensive, I mentioned that, too. Whether or not you feel it is worth it is your opinion. I, too, would take the extra spell slots over the decreased MM cost, but only because it is in keeping with MY wizard. If he were more of a combatant, the choice would be different. You might have a few more spells, say two for each time you take the feat, factoring INT mod.. However, ALL of my spells will be maxed, intensified, twined, ect., giving me predictability of results, which is a major advantage in deciding ones tactics.
As to an epic feat needing to be more powerful on its own, why? Perhaps it was poor planning, perhaps it was there to give those willing to make the investment a big advantage over those who think it is useless. The greatest power comes not from a single feat or class, but from a well thought out combination. Damn, I'm repeating myself again.
And for what it's worth, I don't remember you sighing at me when I have agreed with you in past threads. You are't impressing me by doing it now.