minus costs of exploration (of which as producer free carrying other participants you must pay)
minus costs of production and financing of bringing to production
minus costs of discounted cash flows
minus riskyness of assets
minus taxes
minus admin
minus costs of future exploration
CRAIGC25 - don't overestimate the risk in this (or the chance it isn't all is hoped). This will give you a more accurate price.
For a comparision look at AIMR. $2 billion resource, £20 million market cap, positive banking feasibility study, but then the cost to build the mine is $75 million and if this is raised by placing this reduces the possible upside to something like 50%-100% using discounted cash flows.
If germany comes up trumps the price will be 5 times this but the chance of that is less than 10% (probably more like 3% - look at the data).