[Jay]

Assuming 80 WIL, 25 Power Tome, Mancy's out the wazoo, let's assume that your character can manage 120 damage spells, with a 130 damaging spell in there somewhere.

Lets not forget the cheap FP costs of mage skills. A fir would only cost 8 FP to dish out all of that damage. WIL+2 and all. You can easily calculate the destruction and convenience from that alone.