... for the nickel ore.
About a couple of years ago there was an estimate of 120$ per ton.
Now = "estimated operating costs (including road access fees) of $97 per tonne"

Sooo, where did the 20$ saving come from?

I suspect mostly from abandoning the pipe and going with the N/S route. So that is the reason for the change. The pipe was a safety just in case we had to go alone and as a bargaining point in case we were asked to contribute more to the N/S route.