I believe the idea can work, only if you will make some other way to "level up". Players should be doing something, ONLY to be getting the level up. Now if it costs adena, players will just have to click 100 times and they will have their level, doesnt look like fun.
For example:
- Kill specific monsters which drop specific spell books
- Quests for mages of each race, you gain reputation by doing some tasks and you can buy buffs of certain race
- You gain extra skill similar to Spoil, to drain Spell Points from monsters. Lava monsters give some fire skills, Angels some holy skills, something like that
The way it works now, i dont see the point.