Aryon gives away overpowered artifacts like candy. :shrug:
"I made this when I was an apprentice centuries ago. You can have it if you like."
(Pawns off Aryon's Helper... Summons a storm, flame, and frost attronach for 120 seconds, with a charge capacity of several thousand.... Yeah.)
So uhm.. Yeah. The Telvanni tend to have some pretty powerful trinkets laying around. They are also insanely xenophobic, and posessive, and like to kill would be theives, so they get to keep their trinkets, until they want to give them away, or bore with them. (Though the DO often steal trinkets from each other... I seem to remember nicking a flame mirror robe for somebody.....)
Anyhow-- The Telvanni could produce huge quantities of wealth just by employing good tailors, then enchanting the BEJEEEBUS out of those items, and selling them for a premium.