limited funds - which spells are essential?

[Dural_Levant]

I am only a lvl. 6 Druid, but I scoped out the price of my level 9 and 14 spells. I will not be able to afford them all when I reach those levels so I need to know which spells are considered "essential" and make sure to save up for those first.

The spells with an asterisks before them are spells I am already sure of that I need to get.

-Level 9-
Endure Cold
Enduring Breath
Firefist
Ignite
Invisibility versus Animals
*Light Healing
Shield of Thistles
Starshine
Strength of Earth
Thistlecoat
Treeform

-Level 14-
Befriend Animal
*Bind Affinity
Cascade of Hail
Expulse Summoned
Halo of Light
Invigor
Levitate
See Invisible
Skin Like Rock
*Spirit of Wolf
Stinging Swarm
Summon Drink
Summon Food