I like the general idea, I did not like the implementation much though. Master spells where only for raids and thus rather hard to come by for the avarage gamer (unless you were willing to pay ridiculously high prices).
I'd much rather see a "skill/use" kind of progression once you earned a spell. Or, alternatively, a quest progression. Dropping spells in a regular fashion just isn't doing it for me. Sure, you can have 1-2 spells drop, and that really is quite cool, but not that many, especially since some classes are more common than others, with all implications on spell availability
