"On average, the cost of producing iron ore in Australia is $30/tonne, compared with $40-50/tonne in West Africa and $90/tonne in China. Production growth in Australia will stagnate over the longer term, and Fitch predicts production to actually peak around mid-decade at around 1.05 billion tonnes.22 Feb 2021"

Hmm ... some years back the cost of production was more than double that and was marginal... if this is all true then this is a windfall for some.