So, you can buy apprentice and novice level spells from any hold mage but where are the more advanced spells? Your perk trees give you "half cost expert and master" level spells but where are they? After exploring most of the game I finally made it to winterhold and the mage's college where I figured I would finally find these more advanced and more potent spells. However, they don't have anything more advanced either.

I hate coming here for spoilers but ffs.... this is ridiculous. When the advanced spells can't even be obtained at the mage's college...

Seriously... where else would it make sense that they would be?

I believe that the inventories change as you level, but I'm not sure. I know that there are specific Quests for Master Ritual spells, but again, don't take that as scripture...

I was able to buy adept spells from the trainers in Winterhold when I had lvl 40 in the corresponding skill. My Redguard warrior/thief's highest magic skill is 57 (restoration) I'm guessing expert spellbooks are available at 60...