Couple of points:1. "(about US$75/t) of export thermal coal...

Couple of points:

1. "(about US$75/t) of export thermal coal including all sustaining underground capital expenditure"

2. The US$61.00/t was in a PFS, thus it will be reffined when going into a BFS, that is why they do a BFS.

and most importantly

3. From Dec 2010 - "Estimated US$40-US$70m capital cost to be funded from operating cashflow and debt funding". and "given the positive results of the Pre-Feasibility and Mining Studies and the lower risk profile and the capital expenditure associated with a planned initial opencast mining operation."

Those figures were for the opencast operation BBB. Going by todays announcement there could be significant saving for the whole open cast and under ground mine anyway.
Cheers