I bought some more when it was around $150, but it's still looking attractive at $168 today. As always, nobody can say for certain which way the prices are going, so if you want to buy in and don't have a good reason not to, you can start today.
Dollar cost averaging is an easy strategy. Decide an amount that you want to purchase each week, like $10 or $100 - or 10 Steem, and buy on the same time every week. That way, when the price fluctuates, you don't have to think about it too much. If the price goes up, you're buying less and if it goes down, you're buying more.
I do expect that the crypto market will continue to go down for a month or a few months, with Bitcoin getting under $5000 - which might mean that Dash gets below $140. But again, nobody knows the future.