But do these qualify as aircraft? I would see the US Space Shuttle to be more of a cross between a glider and a brick. It can't really take to the skies under its own power, and is not primarily designed for operations in the atmosphere.
Same with the Apollo program. They simply pass through the atmosphere. No an aircraft doesn't need to be reusable...and I know a few that don't land on tyres, but the Apollo capsules really only fell out of the sky after missions
I like the idea of this topic, though. Especially if "expensive" can be viewed in the time of each aircraft. What was expensive then is often shadowed by more recent projects.
Under that argument... the Wright Brothers had the most expensive aircraft of their time!