I think what 4e did with the idea of rituals and attack powers was close to what is needed. The problem was how they did it.
Each spell should be split up by resource.
Weak spells: Cantrips, Ray of Frost, Feather Fall
Time consuming spells (minor communication exploration spells. Usable outside of battle when time permits) Water Breathing. Remove Poison. Hide from X,Magic Circle against X, Detect X
Slot consuming spells (bigger effects. 5 a day or so) Fireball. Sleep, Heal, Summon X
Gold (via components) consuming spells: Magical Crafting, Wishes, Raise Dead, Permanency
Each spell should be split up by resource.
Weak spells: Cantrips, Ray of Frost, Feather Fall
Time consuming spells (minor communication exploration spells. Usable outside of battle when time permits) Water Breathing. Remove Poison. Hide from X,Magic Circle against X, Detect X
Slot consuming spells (bigger effects. 5 a day or so) Fireball. Sleep, Heal, Summon X
Gold (via components) consuming spells: Magical Crafting, Wishes, Raise Dead, Permanency