If you have an Xbox one, go check out the "deals with gold." Alien isolation is on sale for $18, and the season pass is also on sale for $15.
Update: here's a link
http://www.gamespot.com/articles/this-weeks-xbox-one-and-xbox-360-deals-with-gold-r/1100-6430799/
Update 2: looks like it's on sale for $15 on the Xbox 360, with the season pass also on sale for $15.