Ann: Quarterly Activities/Appendix 5B Cash Flow Report, page-40

These are Domestic Thermal Coal sales FOB barge at Batu Tuhup. If they sold international at Taboneo, FOB ship about usd$150/tonne with bonus for low ash, sulphur, low moisture, high CV.
But up the river have to deduct barging and whatever domestic discount applies.
I would guess USD$110. Too low? Not really!!!
There is no thermal or PCI in Pit 3. On the top of the top seam there is oxidation so it is not Coking coal anymore but it can be sold as high CV thermal.
So this thermal pays for the mining the surface overburden and the coking coal is cheaper to mine.
.ALL IMO DYOR