Some stations consumed certain items to make others so over time their stock levels would drop and they would offer more and more money to restock.
Yet the price of what those stations produced didnt reflect the prices of the raw materials needed, and stations making what should be large profits just swallow the money into oblivion, and when stations should be out of money they magically have an endless supply anyways.
The elephant in the room is that its not an economy. In an economy the actors are each trying to benefit from their transactions, most transactions are wins for both parties, consequences when they aren't, motivation to eliminate losses, motivation to reinvest gains, and so on. Thats just not happening in these A.I. economies. Its not even close.
Now, I am a firm believer in duck theory. It doesnt have to work at all like a real economy, all it has to do is look like it does. But again these games fail for the same reasons I pointed out above.
The best simulated economy in a game that I am aware of was in Capitalism II released over 15 years ago, and even that had serious flaws, but at least the competing A.I. CEO's could go broke and tried not to.