Can someone please explain to me the current valuation of...

Can someone please explain to me the current valuation of companies that have substantial copper and gold resources? Oz minerals recent option to acquire Havilah's Kalkaroo project for up to $400m is a prime example. Prior to the offer, their market cap was around $50m , despite have a JORC resource of 1.3 MT copper and 3.2 Moz gold in SA. This project alone has a NPV of almost $1.2 billion, and is easily mineable (open pitable resource). I understand discounts have to be given for risks associated with getting the financing needed to mine, but still seems extreme discounts are present.

Coda is another one. Whilst having a far lower grade and deeper resource to to what Carnaby will, it still contains $5.5 billion worth of copper in it's JORC resource plus silver credits and only has a $50m market cap?

Obviously this market wide sell off hasn't helped, hopefully more reasonable valuations will return, and value Carnaby accordingly for the extremely high grades and near surface future resource. Painful!