I do agree that even as a regular iron/nickel asteroid is potential value is mind-blowing.Mundane nickel-iron asteroids often contain very high concentrations of precious metals relative to the surface of the Earth.
This asteroid is 140 miles in diameter. It's iron and nickel content alone, if it could be sold at current prices (obviously it can't, but this is just for scale purposes) is dozens of trillions of dollars. Relative to the nickel-iron content, the precious metals are a small portion, but still far greater than what's been extracted by humans thus far.
However, my problem is with the article linked in OP from RussiaToday where is saying "The massive quantities of gold, iron and nickel contained in this asteroid are mind-blowing"
Edit: guess we will have more data in the next 7-8 years if the NASA mission actually takes off