Three things...
I wouldn't change the spell-casting classes...I think it is better to use campaign world restrictions instead...IMO it adds more flavor. I recommend the following (some of which have already been mentioned):
(1) Power Components: Require power components to fabricate magic items and cast certain spells whose use you want to limit. This allows a built-in mechanism to limit the amount of items that are created and floating around because it makes them harder to create and makes certain spells (transporation and raise/resurrection in particular) more difficult to cast. The PCs may have to go on an epic quest just to get the materials to craft certain items.
I wouldn't recommend using power components for everyday spells, but make sure that there is no "ready market" for such components. Obtaining them should be an adventure in and of itself.
(2) Item Creation/Metamagic Feats: Require a tutor or other restrictions to learn these. For instance, the Royal Magician's Guild doesn't want just anyone learning how to create magical armor or wonderous items, so a prospective student must apply to the guild, be tested and be approved before the feat is taught.
Also, the guild may require that all magic items created are registered with the guild, have a special "maker's mark" on it and the authorities come down very hard on mages who create magic items that are used in crimes. Of course, there is an unregulated "black market" but items and/or training are much more expensive!
(3) Magic Item Availability: Because of (1) and (2) above, there is no ready market for magic items. The PCs either have to create them, find them, steal them or deal with the "black market" for them.
If you implement these ideas or variations thereof, it should go a long way to limiting magic overload if that is your goal.
Old One
I wouldn't change the spell-casting classes...I think it is better to use campaign world restrictions instead...IMO it adds more flavor. I recommend the following (some of which have already been mentioned):
(1) Power Components: Require power components to fabricate magic items and cast certain spells whose use you want to limit. This allows a built-in mechanism to limit the amount of items that are created and floating around because it makes them harder to create and makes certain spells (transporation and raise/resurrection in particular) more difficult to cast. The PCs may have to go on an epic quest just to get the materials to craft certain items.
I wouldn't recommend using power components for everyday spells, but make sure that there is no "ready market" for such components. Obtaining them should be an adventure in and of itself.
(2) Item Creation/Metamagic Feats: Require a tutor or other restrictions to learn these. For instance, the Royal Magician's Guild doesn't want just anyone learning how to create magical armor or wonderous items, so a prospective student must apply to the guild, be tested and be approved before the feat is taught.
Also, the guild may require that all magic items created are registered with the guild, have a special "maker's mark" on it and the authorities come down very hard on mages who create magic items that are used in crimes. Of course, there is an unregulated "black market" but items and/or training are much more expensive!
(3) Magic Item Availability: Because of (1) and (2) above, there is no ready market for magic items. The PCs either have to create them, find them, steal them or deal with the "black market" for them.
If you implement these ideas or variations thereof, it should go a long way to limiting magic overload if that is your goal.
Old One