Yes.
1.no company rejigs their PFS every time the price changes
2. Yes. But they get a US$20/t pricing premium - thats where the real profit comes from.
3. No-one includes infrastructure thats already there or is off their sheet. Thats normal. You dont raise the capital, its not on your sheet (refer to Karrara, BC Iron etc).
MFE Price at posting:
3.4¢ Sentiment: Buy Disclosure: Held