Elite Market District

So, the city my campaign takes place in has three separate markets. There's the normal market, the Black Market, and the Elite Market. I've already got most of the Black Market set up (I just need some armor/weapons that might be there), but I have absolutely nothing for the Elite Market because I'm not entirely sure what would even be in there. Any ideas?

If you have magic shops, it seems like there would be at least one of those. But it wouldn’t sell things like +1 swords, those are for those ruffians who go and loot abandoned temples. It would sell things like glamoured pants that make you look 10 pounds lighter. Cosmetics that don’t come off when you sweat — maybe even little illusions like a moving, animated tattoo. Rings that keep your hands warm in cold weather. Maybe there would be some spell components, as well, but only for high level spells.

I’d also see things like high end/boutique jewelry stores, clothing stores and art dealers. A fancy grocer with rare ingredients sourced from around the world, their fish is teleported in every morning. Probably a few of those, actually. Some salons. A couple furniture stores. A rug store. A restaurant or two. A cafe or three. An antique dealer.

There may be a few offices for services (on the second floor as the first is for retail). Things like lawyers, accountants, investigators; all very discreet.

Probably a temple or two to whichever gods the people of that town favor. The donations there help subsidize the temples in poorer parts of town. Or maybe they don’t.

If you’re in a high magic world, maybe a place with a permanent teleportation circle the wealthy can use to go on vacation, and come back, of course. A place that sells basically golems, or other kinds of automaton servants.

In addition to Xalthu's excellent list of suggestions I'd add a pet shop and a florist. Nice opportunity to break out some of the lower CR monsters in the Monster Manual and possibly throw in a small combat or other encounter as they escape. 

I'd also say that as much as a list of shops is good you also need to focus on a list of shopkeepers. Your players will get bored very quickly if everyone they speak to is the same but throw in a few quirky retailers and suddenly your shops are somewhere they want to keep visiting. Look at Critical Role and Gilmour's Glorious Goods from campaign 1 and Pumat Sol and The Invulnerable Vagrant in campaign 2, neither are anything more than standard magic item shops but the shopkeepers themselves were memorable and so ended up loved by both players and viewers

In addition, if you want side quest material, you could have a shop owner or wealthy family that is deep in debt and wants the pc's to help somehow. Also, high-level potion shops, with potions that are flavored as well as magical, decorative (and maybe functional) weapons, armor, and such.

It's a great opportunity to introduce your city to the characters. Throw in cultural details, aesthetics, and things to make your city feel unique. Talk about the smells in the air. The elegant, expensive clothes stylized in the fashions of the region. Local, exotic flowers. I'd recommend keeping food to the other two markets, though, as elites can get their food delivered by porters. This is a place for fine goods, the exotic but not illegal that doesn't fit in your other markets.

I would say the Elite Market doesn't have anything the same two weeks running. I think they're the far-travelling merchants who bring exotic goods from the four corners of the world. You don't go to the Elite Market looking to buy a really good magic sword-- you go to see what fantastic treasures are on offer and come away with whatever you're lucky enough to find there. 

The primary market for their goods are probably other merchants to are looking to distribute rare goods, but extremely well-to-do adventurers might also keep an ear to the ground there in search of ancient knowledge, keys to lost crypts, or potions made with impossible-to-find ingredients.

It depends how realistic you want, vs how gameplay friendly you want to be.

Realistic Elite Market : Fancy clothing, purebred pets, horses + accessories, books/writing supplies, candles, perfume, wigs & makeup, jewlery, ornate / decorated weapons & armour.

Fantasy / Game-play Elite Market : Magic Shop(s), Reputable potions, Map-maker, Enchanter, Tamed-monsters & accessories, Perfumes & Medicines, Gadget & Gizmos (Artificer shop).