Decisions to relocate government agencies to non-metropolitan areas are not made purely for cost reasons. They can also serve government policy objectives, such as promoting regional economic development.
Regardless of the policy objectives that may exist, I would expect that decisions on individual agency relocations would be based on sound business cases. Those business cases would show how the relocation achieves any relevant government objectives, what costs (or savings) would be involved, logistical considerations such as obtaining appropriate accommodation and staff, and any impacts on levels service to the public.
In my view, the existence of government policy objectives does not remove the need for individual decisions to be made in a transparent, rational and accountable manner. Responsible public servants should provide the appropriate information to government to allow it to judge how best to implement its policies.
Parliamentary reference - Report number #147 - released 14 December 2005