CDKeys offers Steam downloads of Stellaris for Windows, Mac, and Linux for $16.59. That's $7 under our mention from last August and $3 less than Steam's current sale price.

They also have Steam downloads of Stellaris Galaxy Edition for Windows, Mac, and Linux for $22.99. That's $12 under Steam's sale price. This includes the base game as well as a novel, collector's book, soundtrack, and other digital goodies.