Do you seriously think it costs 600 quid to make a REPLACEMENT mobo??? So let's get this straight: we've got one poster here who believes that they don't make a profit on £~600's worth of 'other' computer parts. You're not convinced that they make a profit on £600's worth of motherboard.
Could I suggest that one or both of you is wrong, or else there's a company out there that's making a machine for the sheer hell of it???