I'd say, if anyone wants to find the right balance needed to stop working and trade for a living, think like this:
1) How much do you think you need every month to pay your rent, utility bills and other costs of living? I live in France and I'd estimate this amount at around 2000€ to be 'ok-good'.
2) To make these 2000€ you need to get in touch with someone already in the business or any tax expert to tell you how much you need to make gross to 'keep' this amount net (let's say you need to make 3000€ gross).
3) Now that you have a monthly target of at least (don't forget your balance needs to grow) 3000€, you need to look at the strategy that you practice in demo or live on a small account so that your risk is respected (no more than 1-2% risk per trade at maximum). If with this safe strategy you managed to consistently make 5% a month you'd therefore need 3000€/5%= 60,000€ available.
A smooth sea never made a skillful sailor.