Here's a view of the biggest ASX listed West African gold explorers. Which shows, resource, EV per reserve & resource ounce and a break up of their resource by category.
PVM looks cheap especially when cash is taken out of the market cap. When you then consider that the mine lives of all the developers are similar as are the cash costs and that PVM has a significant amount of their resource as reserves, they look cheaper still.
PIR looks pretty expensive, with a resource that is only indicated and inferred and an EV per ounce higher than PRU.