Marli is given stock options to work for Bigco, Inc. She is granted options to purchase 4,000 shares of stock for $10 each. They vest over 4 years. At the end of year 1, 2, 3 and 4, the stock is worth $10, $30, $50 and $80 per share. Marli decides to exercise all possible options at the end of year 3, and makes $120,000. How much potential option profit is available to her at the end of year 4 (not including the profit she made when she exercised in year 3)?