Well interesting you ask that Larry, I did that last night as part of a matrix on SI:

http://www.siliconinvestor.com/readmsg.aspx?msgid=30492880

If using 30k tons per year, $8k per ton and 10% discount, I got $290M USD NPV. This underestimated ZEN's calculated NPV even with the additional $500 per ton.

So if the matrix underestimates in the low end, it certainly was not built to pump. How this variation changes as the numbers move up is hard to know but if it had over estimated the NPV, then I would agree with you that it had a major skew to increase the NPV. As it stand, this is not the case!

Glorieux.