Deal of the Week promotion.
For $5, you can snag Far Cry Instincts Predator, Far Cry 2 or Far Cry 3: Blood Dragon. Dropping $15 will get you Far Cry 3, while an extra $5 will secure the "Deluxe Bundle" DLC full of additional single-player missions, unique wild game to hunt and a variety of weapon unlocks for the campaign and multiplayer.
Far Cry 3 was very successful for Ubisoft and helped to steer the company toward focusing on more open-world games. Ubisoft has said Far Cry 4 will "clearly" happen and Drive composer Cliff Martinez mentioned last year that work had already begun on the sequel. Ubisoft has yet to officially announce the next game in the series.