Less than two weeks after release
On August 22nd, Guild Wars 2: Heroic Edition released, around the one year anniversary of the Guild Wars 2 game's initial release.
Today, you can save $13 right off the bat, giving you Guild Wars 2: Heroic Edition for only $36.99. Along with the base game, the Heroic Edition affords you three bonus items - Legacy Armor, a Mithril box with 18-slot inventory expansion, and ten Experience Boosters that'll each give you an hour of 50% extra experience.
This makes the cheapest time to buy Guild Wars 2: Heroic Edition since its release.