Black Market ware ideas??

So I'm a new DM. This is my 2nd campaign, uh, ever, and I decided to punish myself by hand-writing it. The characters might end up going into the black market in an upcoming session, and I'm desperately trying to figure out what kind of creatures would be sold on the black market. This includes intelligent species, although small enough or whatever to be caught and traded.

Any ideas/tips?

Manticore eggs, dreamsand, pirated goods, weapons, poisons, curses, basically anything that's dangerous, rare, stolen, or all three. 

Drugs that make you fall into a dream you can control but withdrawal is lethal, and the dreams get longer every dose you have until you never wake up.

Pixies slaves are good if you have some way to force them to cast their OP 1/day spells.  They could also sell a 'charmed Quasit' which they assure you it is totally dominated or your money back (not dominated at all),

Scrolls of 'illegal' spells, which depending on the government, might include:

Krail's Maggot (From Book of Ebon Tides - necromancy that puts a maggot in you that eats you), Invisibility,  Animate Dead, Summon Lesser Demon, Charm Person

And of course, poisons of all kind, particularly ingestible ones.

High Elf ear rings - rings made from High Elf ears.

Burning rash poison - causes 1 point of fire damage and heals 1 point. The constant burn causes disadvantage on all checks.

Think what creatures have applications in your world, and drop them in your market.

Warring kingdoms? Sell mystical beasts or soldiers of war, like controlled minotaurs or bound devils. 

Also think about what kinds of creatures slave owners might consider to be useful in the line of work that they want them to be forced to work in. Big, strong creatures with no particular intelligence would be good for farming, while more elegant and sophisticated creatures would be prized as waiters and courtiers.

While you are thinking big. Think small as well. Black markets can include every day things that are difficult to get legally or have a high tax rate. Think buying spices from India while living in England. Legal and taxable. Or cigarettes, alcohol or explosives.

So maybe, exotic pink salt is for sale as well as poison. Perhaps, Dwarven forged weapons are next to Pixie sleep dust. Possibly have rare insects next to smokepowder.

Look to real life for examples to change into a magical twist.

Things that are illegal because theyre evil: slaves,  addictive drugs, evil magic, evil  potions, evil scrolls, spyware,  mind control, murder from a great distance, etc

Things that are heavily taxed: any item that is imported, any item produced locally but used nonlocally

Things that are dangerous and heavily regulated or illegal: drugs, dangerous animals,  weapons, 

Things that are a threat to those in power: anonymizers, weapons, a printing press,