Is there anywhere to buy Adept and above Illusions spells other than Winterhold College? Farengar and the court Wizard in Dawn star don't sell above apprentice level.

I have a feeling not... but if there is, I would like to know too.

Try the court wizard in Solitude. And make sure your Illusion skill is high enough (needs to be at least 40 for the spellbooks to show up in her inventory).
She'll only sell Adept spells, for Master you need to join the College.

Thanks, I'll look in Solitude.

The Strategy Guide says that Spell Tomes are available as loot at earlier levels than required. Something about you have to be a certain level in a particular school of magic to find Tomes from vendors, but your overall character level allows you to find them in loot earlier...

Yeah, you have to be a certain level to get higher level spells from merchants. After you level up some more, he'll have better spells.

I think the only place is the college.

You can purchase Adept level spells from one of the non-college mages (Solitude, I think), but all Expert spells are only available from the college Illusion teacher. I had to join to get my beloved Invis spell. There are some times that the professors are in the town of Winterhold - in the inn mostly, so you may be able to buy from them as a non-member if you are a high enough level. Never tested if they are 'members only' vendors. The Thieves' Guild guy will definitely sell to you when he's in Winterhold, but he doesn't sell Expert Illusion spells, afaik.