Well if you want just a WAG you can go to RS Means and look at their numbers. For yours, I would imagine worst case is a 2000A, 480V,3PH,4W they have at $52,500.00 + the distribution panel at $69,000.00 for a total of about $122k. This is for service and the main panel only. Then you add all your distribution, panels, etc....
RS Means is well suited for this, but you need to know that many factors will influence the end numbers, location, market, yada, yada, yada....