Spells: Greater Healing

[Crust]

For Cleric 150 mana 3.8 cast level 30 heals for 300 hp

For Ranger 150 mana 3.8 cast level 57 heals for 270 hp

why are these inconsistent? The are the same spell. Are there differences for all class' or are some not functioning correctly?

Thanks for all your hard work.

Crust