I (think I) remember in Oblivion that I earned my various levels of mage robes by completing quests. Is it the same in Skyrim? I think I'm still a novice but I found a more experienced mage who can sell me an apprentice level robe -- and, more importantly, I can afford it ... Is it OK to buy it, or do I have to wait to earn it?

It's okay to buy it. Things don't work like they did in Oblivion....

The 'best' pre-enchanted robes are obtained at the very end of the College of Winterhold quest-line. But yeah, but away, because you don't rise in ranks so much like in Oblivion.

Thanks, all. Maybe these robes will keep me from dying quite as often ...