I understand what you are saying but its an oversimplification...

I understand what you are saying but its an oversimplification (and its why markets even exist - speculation), CATH never negotiated for a controlling interest, they only wanted the output. CATH also brings in more than just a $ amount of Capital its more strategic.
A US partnership would bring in different value too but the US don't want to partner, they want to own the whole thing - which has its own value different from the CATH deal.

AVZ is a one of a kind item, you cant pass on it, then go buy the next 669MT Lithium and tin mine - it doesn't exist. Thats why the value cant easily be measured and there is a reason Kobold want to come in and own 100%. The value on offer you suggest, is no way near its potential and no way near fair value (IMO) but thats why NF is/has been negotiating nonbinding.