Pet Dragons spells too rage-expensive

[eXeel]

I am a mage and at lvl 32, my pet's spell upgrades begins to cost 50-60 rage for the next upgrade. And I have 53 or so. And it takes 3-4 rounds to get up there.

What should I do?
1) Upgrade the most useless spells, to not make my primary spells too rage-heavy.
2) Upgrade the most used spells, so they are good and ready when I find a way to get more rage.
3) Or...?