I play as a Breton who uses Conjuration spells and the Magicka Absorption bug is really annoying if you have the Atronach stone. Therefore, if you want to use conjuration spells, the Lord stone is a very good alternative for a Breton. You can reach the 85% Magic Resistance cap without any enchants, you save two alteration perks and still have 50% Magicka Absorption once per day. Besides, with the Lord stone a properly perked Ebonyflesh will give you 350 Damage Resistance which is more than enough for a mage. On the other hand, the extra 50 Magicka points of the Atronach is not that useful considering that you will probably enchant your gear so that you can cast spells from one or two schools for free.

Grab any unenchanted robes and throw 25/25 cost reduction on them. The Archmage robes are probably one of the biggest noob traps in the game.