This item is acquired in-game. See its sources below.
In the Appearances collection, Colossian Cuirass is listed as World Drop. Appearance ID: 80070. 1 other item wears the same appearance:
Read from the World of Warcraft client build files.
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Colossian Cuirass suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Colossian Cuirass is part of the transmog set Zaralek Surveyor's Expedition Gear (Warrior, Paladin and Death Knight only). The other 16 pieces:
Zaralek Surveyor's Greatcloak
Zaralek Surveyor's HelmZaralek Surveyor's Breastplate
Zaralek Surveyor's Sabatons
Zaralek Surveyor's Gauntlets
Zaralek Surveyor's Legguards
Zaralek Surveyor's Mantle
Zaralek Surveyor's Girdle
Zaralek Surveyor's ArmplatesKarokta's ManeGreathelm of the EmissaryCrystal StompersCrystalpod GauntletsGuardian Golem's LegplatesDeepflayer ShoulderguardsGreatbelt of the StronkBuilt from the World of Warcraft client build files and recorded Auction House snapshots.
Colossian Cuirass is not traded on the Auction House, so it has no live market price. It is acquired in-game from the sources listed above. This page collects its first-party game data (identity, effects and where it comes from) from the official World of Warcraft client build.
TheWoWDB