Plate is warrior, paladin, and death-knight gear, and tanking plate with defensive stats holds a premium over same-level damage plate.
Plate (Armor)
Auction-house prices and price history for Plate in MoP Classic.
1,333 items in Armor › Plate are currently auctionable in Mists of Pandaria Classic.
Prices refresh daily from TradeSkillMaster (TSM), so day-to-day gaps in lower-volume listings are expected rather than a collection problem.
Plate listings link to price-history pages with per-realm buyout, average, and median data for Mists of Pandaria Classic.