No matter how small your capital in trading, you can still make profit if you really have exact knowledge. If you have big amount money, if you enter trading you will only liquidate it. So for me, I'll go with knowledge if you really want profit. You can be rich in trading if you win consistently with your small funds.
Capital helps very well in trading because there are some capital that can give you a good profit. Using $10 to trade is punishment because I do not see how you can turn that money into bigger amounts. If there is a possibility that you can do it, it will take you more time and if you lose along the way, you will be pushed backwards to start again but a trader that has the capital will use that capital well and can make profit than you. Some traders are lucky that they win with their first set of trade and they can turn $100 into $500. But knowledge is the most important thing every trader needs because with knowledge you can always look for other ways to rise capital and use in trading but when you do not have the knowledge despite having the cash you will always be getting bad results. Both factors has their role that they play but knowledge about trading should be more important than capital for trading.