The premise of DSO in this case is that Shree's cost is...

The premise of DSO in this case is that Shree's cost is getting the ore to port in Tassie and selling it there. The rest of the cost is on the purchaser. Back in the day, the cost to do this was AU$75 ish.

I have been using the seaborne 58% fines index to evaluate, though I am not sure I have got that quite right. Nonetheless, it finished trading yesterday at about US$85 - or about AU$120 - fluctuating like a small cap these days

DSO limit via epa permit request is 200,000 tons per annum over the 6 years to empty out DSO portion.

Math away the annual profit off that if you can predict the cost of iron ore...