When I watch my dcity value and it is almost 200 USD

How much did you invest? If you would sell, you can calculate the ROI. Also you might see the value increase which is a theoretical ROI. If you refer to cashflow as ROI, than it is another story.

I plan to build it up to generate 1000 SIM/day and then would split the income, 500 into further developing 500 for ROI purposes and cashflow.