For now market info is free and precise. I would like to have some uncertainty to the market data where you have to buy data (ranging from cheap and rough to expensive and precise) to get the info about the demand, how the competitiors are doing, etc.
Another thing would be to hire a market research team to your HQ. those people would collect the market data and collect customers sentiment for a given city district for you. The more experienced they are the better the analysis, you get it.
Yes, it looks like an extra step to the existing logic, but my idea is to make the market harder to view/predict (just like in the real world). I would like to see some struggle when it comes to the customers data.