gjcl,I think that estimation came from a extreamly optimistic...

gjcl,
I think that estimation came from a extreamly optimistic outlook on copper price. I think I'd prefer to have estimations as to how much copper they can dig up. I can calculate the dollars bit then.

“I believe that when we go into production in 2012, I firmly believe the copper price will be at its highest price ever and believe that $US8-10 a pound is likely. This is my observation from having spent the last six months in Asia and eyeballing the ongoing and planned infrastructure and building projects being undertaken that are going to require copper and other base metals. After discussions with a number of smelters we have also discovered the dire shortage of copper concentrates required for the ever expanding Chinese smelter industry.”

http://www.goldcoastbusinessnews.com.au/process/myviews/gcbn_article.html?articleId=2084