Right now seem to be pretty good. It might dip a bit lower in January, but of course no one knows for sure. It takes a high amount of luck to be able to buy in at exactly the lowest price, so don't feel too bad if you buy some and the price falls afterwards. But January seem like a very good month to buy some Steem! ;)

PS. Don't forget to Power Up the Steem! You will definitely not regret doing that.