I don't invest in stocks based on discounted NPV. I would rather see a pro-forma income forecast like my spreadsheet; which is the reason why I do it. I don't agree with discounting cash flows for the entire project when the loan and cost of capital is paid back well before the end of the project.
PMY's PFS detail is quite good; I was reading through it this morning. Sure it has the NPV discount, but there is a decent amount of detail for me to not have to put so much work into cracking and breaking down the figures to put into my income forecasts.
I tend to shy away from looking at EVs for mining stocks that haven't entered production. Once the mining stock has entered production and has a significant EBITDA; then I will look at metrics like EV/EBITDA and NET DEBT/EBITDA so as to compare the stock to peers.
At the end-of-the-day; people should invest based on their own homework and research.