by ImpalerWrG » Sat Mar 27, 2010 7:58 am
How about you have to 'imprint' example items onto the stand which sets the exchange. When the owners opens the stand menu they would see three 'offer' slot and perhaps three 'bid' slots displaying the picture, quality and number of items. They can take items from their inventory and click them on the slots to imprint the item type to the slot, repeat clicks with the same item type incresse the number and the scroll wheel could change quality. For example you could click wool 3 times in the offer slot, and a silk thread once in another offer slot and then a bar of copper once on a bid slot, a bar of tin on another bid slot and a loaf of bread 10 times on another slot.
Now someone else can use the stand and add the items fitting any bid to receive any of the offer packages, they just drag the items onto the bid and when its complete select the offer then want much like using a real vending machine. Best of all coins are completely subsumed into the system, a coin stack can be used for both bid and offer. This type of interface avoids the need to have a long menu of selections the work of which might be a barrier to implementing such a system and the triple bid/offer greatly improves the flexibility, I trade frequently and in a barter system you really need to be able to give/receive multiple commodities as needs/surpluses can change so rapidly, also the lack of any rigid exchange values between coins necessitate multiple prices their as well. The clear downside is the need to have at least one example of any item being traded for, but remember that the creator/owner of a stand is generally going to be a wealthier player or group of players so obtaining the examples by manual trading should not be too big a barrier, also because the examples are not consumed or held by the stand in any way just borrowing them for a few seconds is possible.