With the decreasing price of Bitcoins, I'd say this is the best time to buy Ethereum and Hold till late 2018, you'll see returns. The graph of bitcoin strongly resembles that of Silver prices 2 years back.

With each Eth for 490$ its a deal, don't hesitate in buying Ethereum and holding them to the moon. Trust me, Ethereum will surely hit 1000$ mark the way it did earlier this year when no one anticipated it.