Steam Siege Booster

Steam Siege Booster sells for $24.94 sealed: the median of 9 completed sales over the last 7 days, as of October 4, 2026.

Packs of this expansion carry Shiny Gardevoir, Xerneas BREAK, Yveltal BREAK, or Volcanion on the front. Released with the set on August 3, 2016, each holds ten cards: mostly Commons alongside three Uncommons, plus a guaranteed Rare and a reverse holo.