I wasn't lucky enough to loot one so i can't attest to the drop rate other than the fact that price is a function of supply and demand. Low drop rate = low supply. Low supply + high demand = high price. When i checked the price before going to sleep, it was 10 million gold in auction, which is high imo. That was 15 hours after event started. Sts may have changed the drop rate when they changed the rarity.
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