It is important to remember this is a long term business that you can scale over time and continue to grow.
The amount that you bring in will depend on the amount of capital you start with. We like to typically look for 10%-20% ROI per month, so you can use that ROI to figure out how much capital you'll need for X amount of profit.
Of course, this is not a perfect answer every time, but it is a good general rule of thumb.
You can also continuously reinvest your earnings to scale faster as well.