Yeah now that you mention it there aren't THAT many traders I would've traded with. Definitely not some random npc.
It's the quest "the law of the order" where you either have to give the "letter from Dwarven queen" to Lohar or the magisters. And I have read it since the questlog is updated.
Nice tip as in only bumping one trader to 100, I guess they restock after some time.
