Life and games (but mostly games) from Tony Boydell: Independent UK games designer, self-confessed Agricola-holic and Carl Chudyk fan-boy.
What was that beardy bloke going on about?
Cost = 1 Steel (!). Whenever you excavate, you excavate like Events do ie. one space per point of Work Rate rather than one cube. However, you cannot further affect the number of cubes you take with Contract Card effects.