Legend

Using your contacts from the Thieves Guild you find the infamous black market in some non-descript building in the bad side of city, filled with the usual criminal sort. The place is independent of the Ebony Claw Syndicate AND the Guild. The "merchants" (Who don't look quite human and probably have a past "heritage" similar to Tanya's, except they don't look nowhere near as nice and probably still keep in contact with their "relatives") here are interested in business first and foremost. Not alliances. There also isn't any fighting here. A sign posted right above the counter states that any fighting will be met with extreme force by the proprietors. This is backed up by the 4 IRON GOLEMS posted strategically in the place and magical barriers protecting the merchants here.

Not surprisingly the prices here are a lot more expensive, but you'll probably find some more unusual items here.

Sword 20 Gold
War Hammer 15 Gold
Axe 15 Gold
Mace 15 Gold
Rope 20 Gold
Lantern 20 Gold
Cloak 18 Gold
Leather Gloves 16 Gold
Dagger 12 Gold
Leather Boots 16 Gold
Rations 5 Gold each
Poison Antidote 30 Gold
Healing Potion 25 Gold each (Heals 6 STAMINA)
Silver Dagger 50 Gold
Silent Strike 64 Gold (Very strong poison)
Potion of Speed 50 Gold
Potion of Levitation 50 Gold
Potion of Strength 45 Gold (Increases SKILL by 2 for one battle)

You can also sell any valuable items you may have for extra gold.

Fine Silk Cloak 15 gold
Silver Candlesticks 20 gold
Hollow Golden Figurine 25 gold
Jeweled Dagger 140 gold
Expensive Silverware 20 gold
Mithril Surgical Items 160 gold
Expensive Wine 100 gold
Silver Ring 20 gold
Gold Ring 30
Gold Goblet 25 gold
Old Book 5 gold
Blue Powder 150 gold (Hanging around the black market you find out that this is actually a powerful drug, selling it will result in decreasing your alignment by 2 points though, since you're contributing to the drug trade)

Buy and sell what you wish.