An Australian iron ore mining company, the largest producer selling exclusively to China, considers expanding production from 230 million tons to 360 million tons annually. The case analyzes the economic viability of a $3 billion expansion project, examining its impact on market prices, profitability, and competitive dynamics. Key considerations include interpreting China’s cash cost curve, calculating payback period, assessing competitor reactions, and evaluating strategic options. The analysis reveals that expansion is the dominant strategy, yielding a positive payback within 5 years despite potential price decreases. The case demonstrates the importance of competitive positioning and strategic decision-making in commodity markets.