Just one of many examples, the building of the Millennium Stadium in Cardiff effectively bankrupted the long-established "massive construction company" who had done it
Well that's what happens when you build a £120m stadium when London gets a £1bn one.
Now the question is, given that the government won't be putting a penny into any new airport, what sort of tender process is the new airport going to have? I suggest you have a double risk - not just the risk of incurring unforeseen extra costs, but also the equally large risk that the airport holding company goes out of business.
Now what was that about the government not putting a penny in?