Tom,
No question some of those courses were crazy expensive. We all know the quote about Shadow Creek, Tom Fazio was given an unlimited budget and he exceeded it
Regarding Pete, you would know better than most what kinds of budgets he had at many of his great designs on crappy sites. One area where you might not be correct though about super large budgets would be some of the desert courses. I wonder what the budget was for courses like Talking Stick (pretty flat barren site) or either of the Troon courses?
Gil once told me he’d prefer a piece of featureless rolling farmland over many others because it allowed him complete creativity.
No question, if you get a site like Sand Hills you pitch yourself and see if you are in heaven but there has been a lot of great work done on marginal land. You have done some yourself before getting the best of both.
Note: We will never know but I wonder what it cost to build Oakmont. Talk about a marginal site that drained horrible and was all clay soils. It turned out ok