Randy,
I really don't have budget info on any JN course. However, as mentioned to Mike, he has been moving a lot less earth lately, at DR, at Cimmaron in Texas, etc. As to the other stuff, I presume irrigation, turf, what not will all cost the same no matter who is building the course. (Don M may chime in on that, so I will say cost the same if apples to apples, like watering equal acreage AND presuming they are taking the same risk with a less than cadillac system.)
That in itself is an interesting question. Do you save money on irrigation to meet budget and take a chance that the big show will be compromised by a brown course. Naturally, many here and elsewhere might think that would be cool, so maybe so. And, its not like they cannot water 24-7 weeks before the tournament, if they choose, because it won't be open for play before that, most likely.
For that matter, we also don't know that the budget won't change. It would seem if there were one project where it should be flexible, this should be it as there are a lot of considerations in this project that probably haven't been well thought out by the owners at this point.
I am not sure anyone has a lot of experience with that, although Pete Dye and Kiawa Island/Ryder Cup spring to mind as a close comparable.
As for Tim's pro bono comments, the budget goes up $300K right off the bat. I also wonder if JN does it pro bono, how much Toro or Rainbird, among others will get twisted to do the same to keep the budget in line. Maybe the largest Brazillian earthmover, as a sub, or Wadsworth or LUI etc. will all volunteer to discount prices just to be a part of it. Many contractors are bidding at cost right now without the specter of great marketing potential.