So i'm deciding if i want to level enchanting so i can make some good cost reduction gear for my mage.

Problem is, by the time i get it high enough, won't that just level my character to the point where i could just buy the desired items at shops?

Yes and no. Depends on what you want to do with enchanting and if you want to involve alchemy or not. Enchanting ensures that you get a good combination of what you want on you items, where as ones you find and ones you buy, may have 1 thing on them that you want and not another. At least with enchanting you can double enchant.

If you have an enchanting level of 100 with the appropriate perks, no shops or found items will even come close to what you can enchant yourself.

^^True.

On top of that, say I wanted destruction to cost me 0 magika. I've never found enough items/armor/clothes that will give me that 100% cost reduction. You can do it all yourself with the right perks and level.

Don't know how but somehow this just inspired me to create a mage. Infinite destruction? Where do I sign up!

Get your enchanting level to 100, then take the 5/5 perks and every perk up the middle of the tree.

Thank you but I knew that
And my oh my how do you have 2000 posts when you joined just about the same day I did?

Grinding his posting skill

That made me laugh

I have no life...lol

Yes you do. The life you make in Skyrim.