The virtual economy of UO was killed by the time the beta test ended. We're talking about the NPC shopkeepers here, not the player owned vendors. The NPCs were supposed to follow things like supply/demand as well as having preferences as to what they wanted. Players got mad as they wanted to just be able to dump any old crap (typically bucketloads of skullcaps) to any old NPC.

The NPC shopkeepers also kept hours, would take breaks & walk around town, etc. That was another thing they wound up getting rid of quickly

Ah yes, I had forgotten about that stuff. A bunch of it was before my time and I only knew about it from other players' stories. Thank you for posting it!

Even with so much of that removed, UO always had the feeling of a living breathing world more than almost any other game.

I've heard stories that the Star Wars MMO captured a lot of the same aspects, at least the positive ones. Not surprising considering Koster's influence on both.

I never played it however, I was too hung up on the notion that anything short of a full on sandbox which allowed all the behaviors people were fleeing would be good enough for me. Took me a while to realize that the only people showing any interest in the types of games I was looking for were the people I hated.

Too late now but you might have enjoyed A Tale In The Desert, a very niche MMO where social dynamics were key. As an extreme example, the players could hold an election for Demi-Pharoah and the winner was entitled to ban one player from the game. Not a character, the player. Campaigns might claim they would just never use this power. On the other hand if someone is a total asshole (e.g. building penis shaped art in your farm and deliberately distracting people from group efforts like moving bits of pyramid) maybe a DP campaign could just promise to ban them.

You can't have a meaningful economy if significant parts of that economy are 'magical' such as bucketloads of spawned NPCs getting bucketloads of scullcaps out of nowhere.

Expecting a reasonable supply/demand for something that gets spawned without limit, and gets harvested as a side-effect of something people want to do anyway, is like expecting a supply/demand based trade in candy wrappers or banana peels; The obvious economic value for most NPC drops is zero, and artificial price fixing is required to make it something else.

Or, if one sticks to their supply/demand guns the skullcaps become worthless and either are avoided by players as a cheap way to skill up or it becomes a gold sink. Both are useful.

NB that in early UO, skullcaps weren’t a drop, they were mass produced as they were the most cost effective way to build stats and skills. Doubly so if shopkeepers would actually pay for them