The fastest way for you to get 50ETH. is looking for a very good ICO and investment. ICO investment at this stage is not really wise. The market continues to decline in the future, making ICO not really profitable. But that's the only way you can get ETH faster
Last year was great year for ICO, this year is ICO winter and people are already happy if they don't lost money once token were listed at exchanges...most people were not happy because they lost money...most time only the projects themself got rich...I think in the current market, best think is just to keep your ETH and in few months maybe is already worth 5x more than now