This could be used to augment, not replace the current system. Each
city would have two kinds of demands -- low profit constant demands
for common items (e.g. baskets, pots, linen, etc.) and high profit
temporary demands for luxury items that could be satiated (e.g. rose
perfume, etc.). Each city would have one or more constant demands and
may get a temporary demand from a pool that would expire when the
demand was satisfied. The set of goods demanded should be a fixed set
to make sure that every city doesn't suddenly want rose perfume -- or
that none ever do but prices and quantities can vary. This would be a
good flip-side to the cities producing goods and it would simulate a
market that can "dry up". This would allow players to pick either
slow, constant trade or high risk trade (or a combination).
John Morrow