warrantless,
You may try to look at something close to home such as Canadian Malarctic or Detour Lake to see their Capex values, keeping in mind that their costs were for a few years ago. Inflation, especially its effect on equipment, would be expected to increase the Capex for Borden Lake.
I would not dare comparing with anything here with those in the Republic of Congo (who would sink billions in there). The $3.0+B was for the Barrick/Gold Corp mine in the Dominican Republic and they are pouring gold. But this is a huge deposit (and higher grades), much bigger than what Borden is expect to contain.
Just my opinion.
goldhunter