Recently Constructed mines in BC for reference (worked on both of them)
Copper Mountain, Start-Up 2011 Summer, Construction Mgrs Merit, on time and within budget
New Afton, Start-Up 2012 Summer, Construction Mgrs AMEC, latest presentation indicates on time and budget,
The thing with CAPEX is it is only as good as the persons/company who is performing it.
Equipment (Major) costs are less risk. Labour and materials used for construction have greater risk depending on who estimates and if they have a good pulse of industry.
Mount Milligan is being managed by Fluor-AMEC JV.
Tetra-Tech (Wardrop) hasn't done any of these listed above but in the olden days Wardrop, Kilborn and Wright Engineers were always main feasability companies.
It is all dependant on the persons involved.