Firaxis' Civilization: Beyond Earth is currently on sale on Steam for a record low of $18.49 (the previous lowest price was $19.99), a reduction of 63% compared to its 'normal' price of $49.99.
However, Beyond Earth launched at $49.99 back in November 2014 and as you'd expect of a game a year old the cost of the turned based strategy title fell to $39.99 in mid-August of this year.
With the start of the Steam autumn sale yesterday, Beyond's Earth price was increased back to the original $49.99 from $39.99 according to the Steam Database, presumably in order to make reduction to $18.49 seem bigger than it actually is.
This doesn't seem to be the case in all regions. In the Euro area the game is on sale for €19.99, down from €39.99.
Beyond Earth brings the iconic series from an Earth-like world to other space, with various factions working to colonise a new planet following a devastating event known as the 'Great Mistake' on Earth.
The Rising Tide expansion for the game was released in October and, as the name suggests, focuses on the oceans.