I have the appropriate "cast novice spells for have half mana cost" perks and additional armor perks, but spells still cost the base amount of mana. Could this be because I'm a werewolf?
Whatever the cost is when you look at the spell in the magic menu is what it will cost to cast the spell. What you might be thinking is that your perks reduce this number shown in the menu but that isn't the case.
Sparks has a base mana cost of 19 per second, but in the image the users cost to cast sparks would be 8 mana per second. What it's really showing in the menu is the calculated cost taking all perks and effects into consideration.