A quick rundown of Dungeon monetization: Shattered Throne, Pit of Heresy and Grasp of Avarice were included with Forsaken, Shadowkeep and 20th Anniversary respectively. Duality, Spire of the Watcher, Ghosts of the Deep, Warlord’s Ruin, Vesper’s Host and an as yet unannounced Dungeon have all required Dungeon Keys which could be purchased individually or have been included in groups of two with the Annual Pass for their respective DLCs. Prophecy is the only Dungeon to have been fully free from when it first went live. And for the future, starting with the launch of the Codename: Behemoth expansion next year Dungeons will no longer require individual Dungeon Keys, instead being included with the purchase of the second DLC released each year. (΄◉◞౪◟◉｀)

Do you often not research things before purchasing ?