I was going the other way. The 30kt greenfield was going to cost...

I was going the other way. The 30kt greenfield was going to cost $1B. It was in the original grant application. You would assume they put some science into it. Trying to BS the US DOE while on your knees begging for money isn't a good idea. So we have a basis of fact/cost to work with.

In the 12 months prior to 30/06/22, they spent $115.5m on property, plant and equipment. $68m was in the Sept 2021 quarter to buy Riverside. From 01/07/2022 to the end of the year they spent $24.4m then another $17.3m this year up to Sept. Excluding the purchase of Riverside, that totals $89.2m. Some of the spend would have been on other parts of the business like the cathode.

Being overly generous, Riverside cost $68m so a greenfield sight would cost no more than $150m including land, construction of buildings and anything else to accommodate a 70kt plant. Now we are down to $850m for plant and equipment for a 30kt AAM plant or $570m for a 20kt AAM plant with existing land and building just like Riverside.

They have (being generous again) spent $50m on plant and equipment at Riverside which can be used in the new 20kt plant (see 3rd paragraph), which leaves another $520m required to build a 20kt plant at Riverside.

The grant is $100m so this leaves ~$420m needed to be raised. Simples.

The only number in dispute (@axle84) is whether you believe buying land, building the appropriate builds and power/ground preparation for a 70kt plant would cost $150m.