For the amount of effort put in one would hope that at least the production cost and iron ore price assumptions be closer to truth than what you have produced. Unfortunately the assumptions used are so wrong.
For a start the production costs missed shipping cost to China($10/t), port charges($12/t) and corporate expenses($7/t). Then the price assumption of $110/t for standard fines is also way too high. When 62% Fe benchmark is trading at $110/t AGO would get only ~$94/t for its 57% Fe standard fines. Taking those into account you have over estimated margin by a whopping $45/t!!!
AGO Price at posting:
80.0¢ Sentiment: None Disclosure: Held