I was speaking of having enough capital to live on.
Trading with $5k till you get to 25k would be a good plan if you have other sources of income.
Still more is better. Comm. & slippage becomes less (% wise) as you move up to bigger positions sizes.
Your point on money (and risk) management cannot be stressed to forcefully. I have seen few traders wash out because they are bad stock pickers,... it is usually because they are bad money & risk managers.