its only perfect to someone who needs those mods in that spot, or those mods at all. Any experienced suit builder would work this way. I personally.. if i really needed these exact mods, those exact resists, in one of those spots... and it was the absolute perfect piece... i prolly wouldnt pay more than 200mil, and it would be way more likely that id go a different route than waste 200m on a reforged piece. Armor is all in the eyes of the beholder, and some value some mods more than others. Me personally... damage eater/casting focus is nice... hell casting focus can be the difference in life and death sometimes... but damage eater especially isn't all that worth while in practice. I'd almost rather have mana increase or more hpr/mr here.
I can tell you though, im a suit buildaholic and i've seen that mod combination a ton of times. i've also seen it sold for cheap like 25mil. people burn the regeneater/arcane wizardry options all the time on barbed kits. The special pieces are when someone makes a piece and doesn't select a second mod, like it comes out with huge mage mods and has 5 dci... or 10 stam and stuff... but 5 hci falls on it. The odd combinations are the more rare... and therefore more valuable things. This combination is common.
My opinions of course =) I hope you didnt actually pay the 600mil or whatever you were offering a few threads back for this combination.