Can we please lower Nami's mana costs a little?

As it stands, I barely have enough mana to make it through a single, fast teamfight with my heal costing 130 mana at rank 5, my bubble costing 60 mana, and my 3-proc slow costing 75 mana per cast at rank 5. And an ultimate that costs 100 mana. It isn't as if Nami is outperforming other supports. She just needs to have enough mana to make it through extended teamfights and as it currently stands, none of the items she wants to buy provide any mana.

EDIT: Based on the high number of downvotes you don't agree. Please comment and explain to me why you have a problem with this. There also seems to be the misconception that I am not conserving my mana. This post has NOTHING to do with laning phase. This is exclusively directed at teamfight-related mana problems.