Centaur(life, secondary school) can cost 11 pips! Assuming 5 power pips and 1 regular. Does everyone realize that secondary school spells count power pips as only 1 pip? Unless a mob or boss has more than about 50% resistance to your primary school spells, or you only roll single pips, there is rarely going to be any use for secondary spells, except to heal. As I level up, now 48, I get higher % of power pips, so didn't notice earlier.
This was explained when you got the quest to see Diego in Unicorn Way at level 7. Power pips count as two pips for you primary school. Therefore skeletal pirate which is a 5 pip spell can be cast with two power pips and one regular pip if Death is your main school. It would take five pips (either regular or power) if Death is your secondary school of choice.
This has been this way since before the patch update.
Secondary spells are useful since you may fight monsters who have high resistance to your main spells. Use zero point spells (wand, shields, prisms, etc) until you get the pips you need.
Or you could have a balance as main school and get a mander who will give you pips.
