Basically we invest expecting a profit. Obviously if we have considerable amount the ratio of the profit will be higher. But the amount of investment depends on your financial strength. For a small scale investor could be better to start with at least $100. If you start the field with your home work you can succeed. If money comes as first goal it is always difficult to survive in this field. Learning is the best Earning as i have experienced in this crypto space. Also do not set a monthly income target at the beginning but improve your skill set which will give you more benefits in the future.