I think it helps to look at the Chart for Historical Coal price in US by Region to gain an idea of what the production cost may be:
https://www.eia.doe.gov/cneaf/coal/page/coalnews/coalmar.html#spot
In the period between Nov 2005 & Nov 2007, the average weekly price ranges are:
Northern Appalachia: $40 ~ $47
Illinois Basin: $28 ~ $36
Powder River Basin: $10 ~ $21
It’s reasonable to believe that they were produced with profitability, and that give us a rough range (below the above prices) of what the ACC costs may be.
We can expect ACC to operate at higher than optimal cost due to the small scale and in contract-mining conditions. HHAPPY did mentioned some estimates in post “Just to refresh shareholders" on 10/01/2008 and I think they are realistic.
The most recent average price for Northern Appalachia coal was still above $100, so a likely gross profit of $50 is still quite healthy IMO.
KT