As an example and for comparable reasons:

read this- https://www.newswire.ca/news-releases/taseko-announces-improved-economics-and-new-820-million-tonne-reserve-estimate-at-its-yellowhead-copper-project-in-british-columbia-872826431.html

recently updated technical work on the Yellowhead Copper Project in Central British Columbia has resulted in a 22% increase in recoverable copper reserves and significantly improved project economics.

We began re-engineering the project in early 2019 and now have completely reworked the development concept," Mr. Hallbauer continued. "Today, we are announcing a project with a pre-tax NPV of C$1.3 billion (at consensus metal price assumptions), a C$500 million increase over the 2014 Feasibility Study.

The leverage this mine has to metal prices is huge, and with only a 10% increase in these assumptions, the pre-tax NPV climbs to C$2 billion.

"Based on the new project development plan, our acquisition cost equates to roughly one third of a penny per pound of copper in reserves, or 0.01x NAV. By comparison, acquisitions of other feasibility stage projects in the past have been as high as 1.0x NAV. Given this project's large ore reserves of 820 million tonnes, its geographic location near a major transportation and infrastructure corridor and its compelling copper/gold/silver exposure, this is one of the best acquisitions in the sector," added Mr. Hallbauer.