Also to note the total hualage distance is between 130-250kms...

Also to note the total hualage distance is between 130-250kms depending if they use the rail siding.
Even if they do not the distance compared to to Iron ridge is about half the total distance.

So if as you say they were charging 43 aud per tonne with 6 aud profit. Ignoring inflation for a moment then you could easily presume that the cost of hauling half the distance would be around 22/23 aud with 3 aud profit. Which means a cost of more like 20 aud per tonne.

Add back in inflation that then your probably looking at more like 23-25 aud per tonne. Assuming all other costs like marketing is say at max 10 aud per tonne.

Wow if they can do this for like 35aud per tonne. Then that is a far bigger profit margin than i first expected.

In total that would come to more like 46 aud per tonne profit. Who cares if the number is not going to be accurate whether it comes to be 50aud per tonne or just 40 aud per tonne. That is still a decent amount of profit we can expect. 23 million aud in total according to my calculations assuming we can get 170 aud per tonne average price.

@ 60-61% fe the discount currently is around 5-10% from 62% all other things being considered normal.