when to take Higher Learning

[lokiju]

I am a level 7 mage, and will have enough runes to get Higher Learning at level 8 (if I find 1 extra magic rune). Should I save it for that, or take the 3rd level in chaos magic first? Or, the first 2 levels of destroyer? Or 1st Learning level for 10% XP bonus?

When did most of you take Higher Learning? It's so expensive! I wish they reversed the costs as the 3rd level seems to be half as expensive as level 1.