In my opinion - at least 10 000 pounds.
My opinion is that one should start with a few hundred USD. Those are most likely donated to the market. After the "donation" phase, the trading capital should be a few thousands and then when the traders reaches the point of consistency 50-100K.
Next year you will have been trading for 10 years and you are still on a DEMO? Doesn't sound like you have a strong case for anything other than wannabeism.For me there is a strong case for starting with nothing, or as near as is humanly possible. I have thrown money at brokers in the past (trading not spreads) and it isn't even fun to see them making as much as - or more - than you do.
I'm trading a demo account on IG at the moment and I shall not put in a penny (OK, £250 minimum) until I have developed a method which I can apply consistently. Don't care if it yields 10 pips a day or 100. As I progress, profits will be retained to allow me to stake more per pip. I'm not looking to deploy adrenalin or testosterone.
I'm flattered that you took the time to consider my case m8. A few things have happened during those years, but I will spare you the autobiographical detail.Next year you will have been trading for 10 years and you are still on a DEMO? Doesn't sound like you have a strong case for anything other than wannabeism.
In reality, you don't need to have a lot of money to start trading, you need knowledge. And 10$ is enough to begin trading.