In Wrath of the Lich King it is item level 245 and requires level 80. In MoP Classic it is item level 225, requires level 80 and sells to vendors for 1c.
Read from the World of Warcraft client build files (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Valorous Aegis Legplates Compares
Who It Suits
Plate is the armor type Death Knight, Paladin and Warrior wear. With Strength or Intellect, Valorous Aegis Legplates suits Arms, Fury and Protection Warrior; Holy, Protection and Retribution Paladin; Blood, Frost and Unholy Death Knight.
Transmog Sets
Valorous Aegis Legplates is part of the transmog set Valorous Aegis Plate (Paladin only). The other 16 pieces:
Blizzard numbers items as they are created, so the named items next to ID 45379 (45374 to 45384) were usually added in the same batch as Valorous Aegis Legplates: the same quest line, zone, vendor or reward set.