[simply Nathan]

I'll just say that I love the idea of

Magery 0 (no spell prerequisites, +20%) [6]
Magery 4 (no spell prerequisites, +20%) [48]

Those nine points could have gone into spells, but are instead used to ignore the whole prerequisite chain notion that they seem to be so worked up over.

I would totally do this even for a 100-point mage. And, because it's useful, internally consistent, and cost-effective, most GMs are going to veto it outright.