i play as a mage with leveled magicka and atronach sign. i make my own potions and use them. two reasons for this:
1. with leveled magicka you need very strong potions to refill your mana supply since it grows and becomes quite large and it does not regenerate because of atronach.
2. i would buy them but vendors usually sell those first that are placed on shelves and i don't want to destroy the arrangements. so i never buy potions ingame.
i restrict myself when i brew potions, sell them and leveling alchemy to balance the game. nevertheless it's modded for some difficulties to need the big mana supply for hard enemies.
it is possible to balance the game with using alchemy. i don't feel like a cheater (and i also don't think my game is too easy) and that's the point of having fun