Also, don't tell developers they can't base the economy off a realistic model.
You can't. For RPG it will be too complicated to implement actual realistic model. There always will be simplifications that will lead to worts case scenario in the end and you will have to put up with compromise like many simulators nowadays.
Artificial one always works better. It requires much less work and gives good enough impression and immersion. If you are looking for economy manager I think DoS isn't for you. Believe or not - it is an RPG after all.