On post 95 SS claimed an asking price of £60 billion for Heathrow and now he says £40 billion. Both are far too high. As Gonzo correctly points out there is a huge difference between £10 billion for a new airport and £40 billion for Heathrow. If SS was right Heathrow's current owners would be determined to move to Boris Island.
All the costs mentioned by SS are pie in the sky, and he has no idea of all the on costs of redeveloping Heathrow. In an earlier post 105 I explained why his estimates for selling Heathrow were so far out. Maybe thats why he reduced the expected yield from Heathrow.