With 100:1 leverage on a $500 account you can go in a max of 36k units, or roughly $3.6 a pip.
Regardless of your unit size, you need a big move to be satisfied with profits, and anyone who has been trading long enough, will tell you that kind of unit size with that account size is crazy. One bad trade (and yes, bad trades happen) will ruin the account, and that's 100:1, 400:1 is 4x riskier.
I used 400:1 when I saw Forex as a get rich quick type of scenario, needless to say, it didn't work out.
I didn't mean to sound rude to him, I just honestly don't see a point in anyone needed anymore than 50:1, let alone 100:1.
To be successful in the trading game, find a sound strategy and then learn and understand the rules of your strategy.