Cerro Casale: Capex increase, what capex increase?

News out of Barrick (ABX) this week was that the estimated capex needed to build the now infamous Cerro Casale gold mine in the uplands of Chile has moved up to a cool $5.25Bn (with a B). That's quite a move and it's hardly the first change of number seen at the project, either, as witnessed by this chart you humble scribe ahs cobbled togethe after doing about 10 minutes' worth of simple Googling:

Find sources for these numbers here, here, here etc. So anyway, it's now been fixed at $5.25Bn and it's hardly likely to change again from that number, is it? After all, they wouldn't underestimate and then revise upwards later on purpose now, would they?