Mammon

Mammon, the Golden Count, Avarice Unchained, is an Archdevil who rules Minaíros, the third layer of the Nine Hells. His rotund, sluglike body is made entirely of piles of gold, silver, and platinum coins. He smiles widely as he tortures souls, with a mouthful of gleaming diamond teeth.
Mammon cares for nothing besides material gain, worse than any greedy merchant or miserly king among mortals could ever hope to be. When he grows bored of a Soul cast into his domain (likely through their avarice in life), he sells it for scrap to Hades, for use melted down and reformed in the Blood Wars. Due to his cunning and greed, his rank would likely be far higher in the hells, were he not known far and wide among archdevils as a traitor whenever gold is concerned.
Mammon has little trouble gaining souls for himself. Explicit bargains are hardly necessary, but Mammon's minions do travel into the Material Plane to make them nonetheless. The devils of Mammon often take the form of gems or precious statues to draw the eye of Adventurers and merchants. Once they reveal themselves as their true fiendish forms, they pull out their copies of The Accounting and Valuation of All Things, a book penned by Mammon himself in antiquity that clearly delineates the value of souls, among anything else the mortals can offer. What seems to be an unimaginable fortune to a mortal dealing with these devils is a pittance in comparison to Mammon's hoard. Even some Chromatic Dragons have been known to be swayed by the riches his accountants offer in bargains for their lives and services. He particularly prizes these, as they sell for an incredible price to other Lords of the Hells for use in the Blood Wars after their deaths.