Cameroon Rail Infrastructure Advancing ???, page-7

"A recent 10Mtpa bauxite export business there cost US$1 billion to bring on line.
Canyon believes its resource is superior, and while Gallagher and his board wouldn't be drawn on the potential cost of a 10Mtpa development at Minim Martap, it's expected to of "a magnitude less".
For what it's worth, arm-waving by Kumova suggested somewhere in the order of $200 million could be possible.
Bauxite production of the sort Canyon envisages producing is understood to currently be attracting a price of circa $70 per tonne."
I liked this bit (the 1 billion referring to Guinea)......and if global trends continue $70 per tonne will soon be a price only wished for.