Being conservative is all well and good but you actually need to...

Being conservative is all well and good but you actually need to be able to justify the reasons why. Without reviewing the full working in your spreadsheet I can see some major issues. The processing costs in the feasibility study are US$12.50/tonne. You can’t just add a 60% safety factor on to that to make it US$20/t. That adds US$15M pa to the operating costs. The unit processing costs will likely also come down with the upsized mill in the upcoming revised study.

There isn’t anything particularly difficult about the processing at Sanbrado, it’s all conventional and no metallurgical issues. You can look at the many other projects in West Africa to see if the costs are realistic.

A lot of technical work goes into these studies and the people who do them aren’t just pulling numbers out of thin air. There is a danger in multiplying contingencies in the different numbers and the knock on effects. By adding extra processing costs for example you also increase the interest expense as debt repayment takes longer.

As others have said, I’m fairly sure Taurus would have engaged their own independent experts before handing over US$200M.