auto managed item prices

[RoguelikeGCS]

For my project I have considered using some kind of auto managed system where prices are based on money supply and item availability/rarity.

Consider this hypothetical example:

A player goes through a dungeon and collects a handful of money; he emerges from the location and heads to the nearest shop; he buys some items from the shop, thus transferring money to the shopkeeper. The shopkeeper is now aware that there is more money in the system, and can put the prices up a little bit (not necessarily proportionately). If the player sells items to the shopkeeper, there will be less money in the shopkeeper's system, so there will need to be a mechanism to track the total money that has ever been put in the system, and the current level of money in the system. This way, the prices can increase even if the money in the shopkeeper's pool decreases. (For example: the player sells something for 100 money units, and then buys something for the same price; the shopkeeper should not count this 100 units as new money entering the system.)

Because the player can go through dungeons and find money, or take it from corpses, it will always be possible for him to afford really expensive rare items despite the increasing prices of items (because prices are only updated per trip to a shopkeeper); the shopkeepers don't know about all the money in the game world.

Another side of trading is item rarity.

There should be some way to account for lots of a particular item being added to the game world, so that the prices of items can reflect the availability of items. Really rare items like artefact neutronium lighsabres etc should cost an arm and a leg; the price should be roughly proportional to the delayed shopkeeper knowledge of the money supply.

[Etinarg]

if the shopkeeper has a monopoly on item trades, he can ask any price anyways. if there is competition, players will sell to the trader (or buy from the trader) who is most to the players favor, unless the other offer something beyond the plain item and the money (warranty, free repairs ?).

So your system should consider the fact if there are other shops nearby. And if there aren't, your calculation is unneeded since the shop is a monopoly and the trader can set prices pretty freely (about as high so that players actually can buy things, but not much lower).

[RoguelikeGCS]

I think it's been mentioned on numerous occasions that the problem with fixed prices is that people can scum through a game, accumulate money, and buy all the expensive artefact items. I just want to explore other ways of dealing with trade in a roguelike.

It doesn't make sense to have inflation whereby the player amasses wealth far beyond the wealth of the combined force of shopkeepers.

If we recognise the often imaginary nature of money (the currency in ancient Rome was for a long time based solely on the popularity of Caesar Augustus), and we keep in mind the fixed value of physical commodities such as gold (valuable not because it looks shiny, but because it can lie in the sea for a thousand years and not tarnish), platinum, marble etc, we can see that it doesn't make sense to have fixed prices, while the money supply constantly increases.

[Etinarg]

I see. I didn't understand the problem that you were addressing with your proposal, so my reply came from another point of view.

For single player games the problem is not really a problem I think. Players play alone and do not hurt anyone but their own gaming experience with their actions.

And it seems linked to the question if valuable items are for sale in shops at all - Diablo II has only ordinary items in shops, so the countered the problem in a different way.

In MMOs the value of money is a real problem, but often player-to-player trades dominate the economy there so shopkeeper prices are only a secondary influence. Still inflation or sometimes deflation are real bad problems for some MMOs.