The "Starter" skills are require [Mastery] Rank 1, but all spellbooks you can purchase require [Mastery] Rank 2.
The "upgraded" versions may be separate from the normal versions because they might have a higher AP cost and cooldown time, so there may be cases when you'd rather cast the lesser version now instead of waiting to be able to cast a more powerful version.
I definitely want to pick my starter skills myself, but I hope that will eventually be part of character creation.
