This item is acquired in-game. See its sources below.
In the Appearances collection, Maddening Seaweave Breeches is listed as Profession. Appearance ID: 41044. 3 other items wear the same appearance:
Read from the World of Warcraft client build files.
Cloth is the armor type Mage, Priest and Warlock wear. With Intellect, Maddening Seaweave Breeches suits Discipline, Holy and Shadow Priest; Arcane, Fire and Frost Mage; Affliction, Demonology and Destruction Warlock.
Maddening Seaweave Breeches is part of the transmog set Oblivion Cultist's Robes (Priest, Mage and Warlock only). The other 16 pieces:
Maddening Seaweave Gloves
Robe of the Fallen Keeper
Cowl of Unspeakable Horrors
Spaulders of Miasmic MyceliaVisage of Nightmarish MachinationsRobes of UnrealityVoid Ascendant's MantleTrousers of Peculiar Potency
Void-Drenched Wristwraps
Psychic's Subtle Slippers
Mana-Infused SashEmberscale GlovesBinding of Dark HeresiesCorporeal Supplicant's TrousersBoots of Wrought ShadowCuffs of Grim ConjurationBuilt from the World of Warcraft client build files and recorded Auction House snapshots.
Maddening Seaweave Breeches is not traded on the Auction House, so it has no live market price. It is acquired in-game from the sources listed above. This page collects its first-party game data (identity, effects and where it comes from) from the official World of Warcraft client build.
TheWoWDB