I would say $500 into 10 coins. It's not always good to spread yourself too thing! While you don't want to miss out on future gains, 50 coins may be a little large of a portfolio! Be careful though, just because a coin is 'cheap' it doesn't mean it is 'undiscovered' usually if a coin is cheap then it may not reach the kind of price levels of btc or eth simply because the total supply of that cheap coin is so high.