Sadly, from what I have read that was above average with many paying a buck a day. Here's the point. Even if we paid double that it is less than $70,000 a year for labor. It is pretty cheap. I'm guessing the fuel cost are one of the higher expenses. It also seems that area is known for it's high quality diamonds from just a bit of research and that is most likely the other prized material of which they are speaking.