What Do The Black Market Merchants Sell?

Does anyone know what the merchants Musical Merchant, Exotic Potions Merchant, and Banned Items Merchant sell?

Just to clarify, the merchants that I am talking about are in the Black Market, outside the Letvus Airbase, in an are used by the quest Acquiring Credentials.

I saw a thread where someone was asking about them selling "Unknown Items", but they said that they used to sell "actual, unique items". If they don't sell real items anymore, than i would like to know what they used to sell.

 

Pretty sure they sell (named) red wool.

 

Yeah they're just for aesthetics iirc. There's another one in Almuj which sells a Wybel paw dagger which gives you a bunch of ws.