Those possible Avarice locations are as follows:

The Crucible in Diablo 4 Gold Fractured Peaks: Found towards the east coast of the region, in a northeast direction from Yelesna.Caen Adar in Scosglen: Located on the north side of the region, above both Corbach and Cerrigar.Saraan Caldera in Dry Steppes: On the southeast side of the Dry Steppes close to the border with the Fractured Peaks, to the northeast of the Ruins of Qara Yisu.Seared Basin in Kehjistan: Find it in the northeast of Kehjistan, to the north of Tarsarak.Fields of Desecration in Hawezar: Located in the southwest corner of Hawezar, to the southeast of Zarbinzet.Diablo 4 guides
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If you don't want to rely on guesswork and luck for your World Boss hunting, then you should bookmark this boss timer and tracker feed on Twitter, as it'll keep you informed about upcoming World Boss spawns including Avarice and the others. Anyone can turn up to the designated location and get involved in the World Boss fight when it begins, regardless of whether you've finished the Diablo 4 campaign or not, though players who have beaten the story will get a 30 minute countdown notification in-game about cheap Diablo IV gold the next World Boss spawn.