Ann: TECH Project Feasibility Study, page-257

Why is everyone flat out saying $2.1b CAPEX? For starters it is $1.9b. Going on from there, it is clearly communicated that quotes were taken from suppliers during the peak of equipment pricing. Those prices have already come down and will likely continue to do so.
GM has done their DD around capex, opex, technicals, approvals and funding.. they have seen similar numbers (be it at a lesser point of accuracy) and they still decided to come in with the commitment that they did. At 18c!

We also have a performance guarantee from KBR, 100% offtakes, plenty of debt funding interest and once operational we are printing money and doing it carbon negative!