Yes this the right time to buy eth it's going Cross more than 600$ in 6 or 7 months, so you can buy now, and bitcoin also cross 10k USD soon so buy how much is possible with you.
What's the reason behind that speculation? as I see right now it's always stuck at $300 and just fluctuating a little up or down. Kinda strange even the downhill of Bitcoin and Bitcoin Cash
seem to have no effect to the Ethereum's price, maybe it'll be like this for a long time and there's no guarantee that $600 can be reached within 6 to 7 months.
Just my speculation though, it's not a good time for buying ETH, better go off with more fluctuative coins. Only if you're a trader.