if u wanna to valuate a company u can simple take the number of shares n options issued multiplied by the share price + Cash in bank. to valuate its resources could be difficult unless the company has givne a figure of the estimated figure. I'm not sure what you are asking here, u can mine a huge quantity with low grade js as well as low quantity high graded stuff, just that the cost might be slightly higher than high graded finds, depending on the economy of scale.