In EVE Online, buying/selling goods is done by putting up buy orders and sell orders, and these are located at specific station (the goods will stay at the same station). Personally I find this a bit to much. After loosing a ship, I spent simply to long time buying a new ship and with a decent fitting, where the parts were not bought at ridicilous prices.

An npc vendor/market offers simplicity. You buy and sell everything instantly and one item has one price. In mmorpg games, like WOW, you do have auction houses, but I find these very impractical. Just as in EVE, they're very time consuming. Note that for items that are very rare and expensive, direct player transactions or auction house is probably the best.

In games like WOW, there are npc items, and player made or player looted items. This distinction is the problem.
NPC vendors have unlimited supplies of their own type of items, that are equivalent to player found/crafted items. The items they sell have a constant price, and they will buy unwanted items the player has for a constant fee aswell.
Rather than have NPC vendors offer an alternative to other items, they should sell the types of items players can craft or find. NPC vendors should have a supply of these items, and lower supply means higher prices, and vice versa.

Note that I don't propose that every npc vendor should have their own supply. Supply could be global, or it could be regional. If supply is calculated regionally, then selling to an npc vendor in a given region, will not increase the price of that item in another region.

In Rift, NPC vendors would not sell materials used for crafting (just a few types). I had to use the auction house, or collect it myself. The Auction house barely had any, where most was ridicilously price, or where I would have to wait a long time to get the goods. Rather than this detachment between player run economy, and npc run economy they should be mixed.

Summary:
Players can sell goods to npc vendors, which will increase supply of that good (globally or in a region), which will reduce prices.
Players can buy goods from an npc vendor, which will decrease supply of that good, and this will increase prices.
NPC vendors should sell most types of goods available.

Additionaly, the game should be made so that every item sold by a vendor, must be found or crafted by players.
I do think this is a good solution for mmorpgs, and in mmort's this could be a marketplace
(only individual supply per marketplace, compared to regional/global supply for npc vendor).

Summary:
Players can sell goods to npc vendors, which will increase supply of that good (globally or in a region), which will reduce prices.
Players can buy goods from an npc vendor, which will decrease supply of that good, and this will increase prices.
NPC vendors should sell most types of goods available.

I have to say I love this idea. Is there any game using this?

[quote name='ImmoralAtheist' timestamp='1333063577' post='4926482']
Summary:
Players can sell goods to npc vendors, which will increase supply of that good (globally or in a region), which will reduce prices.
Players can buy goods from an npc vendor, which will decrease supply of that good, and this will increase prices.
NPC vendors should sell most types of goods available.

I have to say I love this idea. Is there any game using this?
[/quote]

Guild Wars has traders, like material traders. Materials are needed to craft items. As far as I know, traders in guild wars will only deal in types of items that are found. They will not deal in items that are player crafted. I would like to see the armor merchant, actually sell the types of armors a player can craft.

In Rift, armors I could craft was very limited. The level difference between two types of a given item, would be about 5-10 levels apart. Armor merchants had their own armor pieces, because naturally crafting would be useless if they sold what players could craft.
I say, let armor merchants sell the armor pieces that player crafters sell to npc vendors.
This also applies to other items. Not just armors.

An NPC only providing basic materials for crafting is almost the same as the players gathering basic materials through mining/farming/extraction for crafting. Just one has a different label and interface to the other. You're pumping resources into the system at the player's request, at some cost, albeit maybe a small cost, whether it's money or time or inconvenience. You could have a regional bias in the resource extraction, but like you say, you could also regionalise the supply chain of the NPC vendors, depending on the game. But from a net wealth balance it's exactly the same (value in - value out = accumulation).

Summary:
Players can sell goods to npc vendors, which will increase supply of that good (globally or in a region), which will reduce prices.
Players can buy goods from an npc vendor, which will decrease supply of that good, and this will increase prices.
NPC vendors should sell most types of goods available.

Additionaly, the game should be made so that every item sold by a vendor, must be found or crafted by players.
I do think this is a good solution for mmorpgs, and in mmort's this could be a marketplace
(only individual supply per marketplace, compared to regional/global supply for npc vendor).

Mortal Online is planning to implement a broker system; an NPC waits in town and you make them trade your goods to buyers, but with a transactional fee. That way your physical presence isn't required for trade and it sinks some of the money in the game.

I believe that's the same as what you're describing?

In EVE Online, buying/selling goods is done by putting up buy orders and sell orders, and these are located at specific station (the goods will stay at the same station). Personally I find this a bit to much. After loosing a ship, I spent simply to long time buying a new ship and with a decent fitting, where the parts were not bought at ridicilous prices.

An npc vendor/market offers simplicity. You buy and sell everything instantly and one item has one price. In mmorpg games, like WOW, you do have auction houses, but I find these very impractical. Just as in EVE, they're very time consuming. Note that for items that are very rare and expensive, direct player transactions or auction house is probably the best.

What you need to remember is that convenience isn't always great; well ok, it is good for most games, but for an economy-driven game it isn't. Sometimes you want to subtly guide your players to play one way (the barter system is an example of a harsh option). Eve Online works because its players are greedy and want to destroy each other. They think that way because they are in control of who makes profit and who suffers. Stability may be great in the real world, but in the virtual world you want boom and bust of different players/guilds at different times. Again, this all goes back to what is the endgame - I'm biasing towards an economy-driven game with lots of PvP, guild cities and all that kind of crap. A game that focuses on dungeon raids, social immersion, skill grinding, PvE etc, would probably want a very predictable, controllable and stable economy. If I was playing WoW, or Rift or any of the latter types, I wouldn't want to spend months leveling up a top character only to find that the type of weapons I've skilled up in have spiraled into high cost and suddenly my character is rendered crap because of the irresponsibility of the wider virtual society.

Oh and before someone smites me, I'm not saying economic-driven PvP is the best idea in the world! It's just an idea of a good MMO and it has been executed in some games.

An NPC only providing basic materials for crafting is almost the same as the players gathering basic materials through mining/farming/extraction for crafting. Just one has a different label and interface to the other. You're pumping resources into the system at the player's request, at some cost, albeit maybe a small cost, whether it's money or time or inconvenience. You could have a regional bias in the resource extraction, but like you say, you could also regionalise the supply chain of the NPC vendors, depending on the game. But from a net wealth balance it's exactly the same (value in - value out = accumulation).

Not certain what you understood from my post, but I did say that NPC vendors would not sell their own basic materials (my proposal). Instead of players directly selling to one another, players will sell materials to a npc vendor. All npc vendors in that region can now sell this item to another player. Vendors are not pumping resources into the system. Goods and money flows through them, where they take a portion of the money. Ofcourse measures must be taken to avoid players from profiting by buying and selling in large quantities very fast.

Mortal Online is planning to implement a broker system; an NPC waits in town and you make them trade your goods to buyers, but with a transactional fee. That way your physical presence isn't required for trade and it sinks some of the money in the game.

I believe that's the same as what you're describing?

From what I've understood, you can place items at a broker as WTS offers. Another player can go to that broker and buy a WTS offers some other player has set up with that broker. This is equal to market at a station in EVE. However, in EVE you can also place WTB offers.
In other words you don't sell items to the broker. You are dependent on another player buying your item from that broker to recieve money.

In what I described, you would sell and buy items directly from a vendor, and one type of item would have a single price (not several offers with variour prices).

What you need to remember is that convenience isn't always great; well ok, it is good for most games, but for an economy-driven game it isn't. Sometimes you want to subtly guide your players to play one way (the barter system is an example of a harsh option). Eve Online works because its players are greedy and want to destroy each other. They think that way because they are in control of who makes profit and who suffers. Stability may be great in the real world, but in the virtual world you want boom and bust of different players/guilds at different times. Again, this all goes back to what is the endgame - I'm biasing towards an economy-driven game with lots of PvP, guild cities and all that kind of crap.

Is EVE an economy-driven game? I'd say economy is an important aspect of it. What I found to be the most important aspect about the economy in EVE, was that every item was found or crafted by players. They could replace the WTB and WTS system with the market buying and selling directly and it would not take away the players role in actually manufacturing/finding the items.

A game that focuses on dungeon raids, social immersion, skill grinding, PvE etc, would probably want a very predictable, controllable and stable economy. If I was playing WoW, or Rift or any of the latter types, I wouldn't want to spend months leveling up a top character only to find that the type of weapons I've skilled up in have spiraled into high cost and suddenly my character is rendered crap because of the irresponsibility of the wider virtual society.

I certainly did not find the crafting aspect very enjoyable in Rift. In what I described crafters would sell items to npc vendors, and npc vendors could those items to consumers. This would also mean you could move npc armor pieces to craftable types of pieces, so crafters would have a larger amounts of items they could craft.
I'd definitely find this more enjoyable, than it's current state, where sold armor pieces are converted into currency and that's that.

Non special weapons might vary in price, but it's unlikey you couldn't afford them. Given they require the same materials to craft as other weapon types, this scenario is not realistic. Crafters would prefer to craft this weapon type due to higher prices, and by that balancing supply and price.
If you're looking for epic equivalent items though, that should rather be sold through auction house (which I did say). However, it is definitely not more in favor of stability, but that's how it currently is in these games.

I find it curious that you seem to want as little player impacted economy as possible in a regular mmorpg, while you're eager to create an economic focused game.

Oh and before someone smites me, I'm not saying economic-driven PvP is the best idea in the world! It's just an idea of a good MMO and it has been executed in some games.

I did not notice you were talking about a economic-driven game. Having WTB and WTS offers adds more complexity than buying from and selling to merchants with dynamic prices. You might still ask how important this specific aspect is though. There are other ways to make players more involved in the economy.
Players Crafting and finding the items available for purchase is definitely important.
You also have the mechanics behind extracting natural resources. I'd want to see something more interesting than EVE's lowsec mining. This extraction of resources is where there's true potential for economic driven pvp.

You make a lot of good points. Sorry about the NPC thing I was referring to how some games have NPCs that just sell infinite amounts of resources.

I'm not making an MMO really, just a text based political, military and economic simulation kind of game thing. I'm thinking of playing Mortal Online after the new update and that is really sandbox economy PvP and bla bla driven.