You cannot extract Part 4 by itself. You need Part 1, Part 2, Part 3, and so on, in the same folder.
New locations for sourcing goods and interacting with the world. Understanding the "GoldBerg" Release TRADER.LIFE.SIMULATOR.2.v6.1-GoldBerg.part4.rar
Prices fluctuate more realistically, requiring you to hunt for deals at the wholesale market. You cannot extract Part 4 by itself