Thats not correct, its 29% of base mana - your mana unbuffed and naked.
At level 60 (for gnomes) your base mana is 3243 so if this were a level 60 spell the mana cost would be 940 mana. So the mana cost at level 70 is probably around 1150.
At level 60 (for gnomes) your base mana is 3243 so if this were a level 60 spell the mana cost would be 940 mana. So the mana cost at level 70 is probably around 1150.