500$ is low money, so I woud suggest you to invest in altcoins : more risks, but more gains
I suggest you have a look at DeepOnion currency : it's quite new for now, but it has a STRONG community (1000+ pages topic on Bitcointalk) and when it's gonna be listed on big exchange sites, the value will pump
https://bitcointalk.org/index.php?topic=2006010.0
Good luck

Recently I have been hearing so much about deeponion and waves as most of the people here on forum have great faith in both of this coins so surely I will think of investing some money in both of them to get better profits in future.