Item level 55 · Stacks to 20 · Prices on every WoW Forever auction house
Large Opal on every WoW Forever auction house, updated hourly. Cheapest right now: 70s 97c on US · PvP · Horde. About 288 sell per day across all markets.
Busiest market
EU · Normal · Horde
Lowest79silver71copperUsually 80silver38copper≈ 60 sold per day