Avalon has a complete economic system, designed to reflect a real world economy (although in miniature). The system can be simplified into two tiers: production of useable raw materials, and the fashioning of the finished products. Both tiers can be carried out entirely by computer controlled characters, though for the most part it is in the hands of the mortals and their gods.
Raw material production takes the form of two skills; that of Farming, which is growing or obtaining the raw materials, or commodities, through growing, or caring for the land and its natrual inhabitants. The other skill, that of labours, deals with the production of the commodities through industrial style processes - mining, drilling, mixing and burning. Both of the skills are long and tiresome to do, but they need to be done. The raw materials thus have value according to their usefulness in finished products, their scarcity, and the effort required to produce them.
Currency will be mintable by individuals for cities and guilds. The value of currency will be determined by its value in trade, in procuring the raw materials and acting in place of barter. At the moment, the currency is the gold piece, this is however a baseline, just like the gold standard used to be the base for various real-world currencies, from which cities and guilds will be able to deviate. Finished products will therefore reflect real values, and city economies and guild or individual wealth will have meaning in terms their currencies, or commodity wealth.