I suggest yoou to better go short term altcoins to make bigger profit like example find 5 fastest growing altocoins and buy 10$ worth all of this 5 altcoins and wait until they grow how much you think that they can and then sell them and make a good amount of profit.
$300 is already good enough to invest for short term to those alt coins that are just going to pump while its ICO. And when the ICO is done they will just going to dump that coin. Better just to buy with that fiat with bitcoin and just hold it for a longer time and you can generate profit by that way.