Perhaps it is a bit over powered... Let's see, that's 1000 damage, before boosts. Sorry, our current 8 Pip spell is a whopping 540-620 damage. So for Holy Flame I would have to say:
50 + 690 over 3 - 8 Pips.
Yes, that's still 710 damage, but it is far more balanced than your spell. Please take this as constructive criticism, and not an attack. Thank you very much for your time.