That's all dependent on the type of campaigns and characters.
They are not alone, but there are not that common either. And even when two parties meet, there can possibly be trade, but it's very different from having shops around the corner.
Well, I usually go by the genre, and they might go to an arena for fighters, or try to find a thief in a thieves' guild if they know where one is, or maybe to a seedy part of town, but there are no "adventurers halls" where you can shop for adventurers of any level when you need one.
The thing is that there are no such places. Are there such places in published settings ? I don't think it's the case, even in the FR. Maybe Eberron, but even when we play there, we can easily get consumables or low level items, but not much more.
First, we don't use artificers, and second I'm not sure that artificers can craft any item they want (at what level do they get that feature ?) and know the cost.
Look, at this stage, I think it just shows that we have very different views about the magic item trade in the settings. I like the 5e approach that there might be some trading if you let people know that you are interested in buying, it might get to the right ear and someone might contact you. But there is as high a likelihood that someone will come to try and steal it or scam you. These are powerful items and they attract powerful nasty people. And while I agree that people will trade anything if they can, they also have to protect their business, assuming that they can even make one, because it requires so much investment and it's so risky. The way I see it, magic items shops just cannot survive, what protection can they buy that will prevent powerful adventurers and thieves from stealing from them ? Who can they even hire to protect themselves ? They would have to be powerful adventurers, and adventurers are not interested in protecting magic shops. And actually, they might actually steal from the shop rather than guarding it.
Now and then, there might be a powerful wizard selling his production (and able to protect himself to some degree), but wouldn't it be better for him to create things for his own use or his own research ? If he's that powerful, he is very probably rich enough to not needing to sell off items.
Actually, our DMs are way better than this (
) they are arbiters of fun, not only of nitpicking monetary rewards and magic items value, because that is absolutely meaningless to some people and some characters, whereas fun is important to everyone who comes playing the game.
What I mean here is that our philosophy is that there are many imbalances in a TTRPG that the system cannot compensate, in particular because the players themselves are imbalanced their capabilities and what they expect from the game. So we think it's better for a DM to balance the fun that people are having, even if it means giving different people different things depending on what they expect. This in turn means that while some people might be interested by money or items, others are not, so some people find riches and others find fame and story, and there is no universal coinage to balance this apart from fun.
Not sure if I'm clear, though...
Which is fine, but 1e was a long time ago...
Yes, I did run a few games in english between France, Canada and the UK when I could get my daughters and their friends online, but two of my players (my eldest daughter and her boyfriend) are moving to Australia, and it's going to become really complicated (I played with Europe when I was in Australia myself, but it was already tough, but my third daughter is still in Canada and it's going to be impossible to manage).