Ability Problem

[Zeffo]

Create this spell and set mana cost:
Level 1: Cost 12
Level 2: Cost 18
Level 3: Cost 24
Level 4: set to 30 and don't work...cost me 24 mana. why work like this?

Somebody explain where I'm wrong

 

[Pyrogasm]

The mana cost is 6 (for all levels, it's in your screenshot), and it costs 6 mana per unit healed so 24 mana.

 

[Zeffo]

yes.