Initial Price in 2001: In 2001, the price of gold was 0.5X plus $300.00 per ounce.
Price Increase in 2008: The price tripled in 2008. Therefore, the new price became 3 times the initial price: [ \text{New Price in 2008} = 3 \times (\text{Initial Price in 2001}) = 3 \times (0.5X + 300) ]
Price Doubling in 2011: In 2011, the price doubled. Therefore, the price became 2 times the 2008 price: [ \text{Price in 2011} = 2 \times (\text{New Price in 2008}) = 2 \times 3 \times (0.5X + 300) ]
Price in 2016: In 2016, the price dropped to 2/3 of the 2011 price: [ \text{Price in 2016} = \frac{2}{3} \times (\text{Price in 2011}) = \frac{2}{3} \times 2 \times 3 \times (0.5X + 300) ]