A change in thinking about ISS

Why would one NOT expect cost overruns. Every large scale program I have
ever heard of, from the Panama Canal to just about every military or
civilian aerospace technology, have gone over budget. How the heck are
we supposed to know how much something we've never done before is going
to cost. All budgets are conjecture. All true, but the way NASA forms contracts, it becomes in the best financial interests of the contractor for there to be cost overruns and schedule slippages. If I could make one reform at NASA, it would be the elimination of cost-plus contracting.