[James2001]

Apparently the French data broadcast on 162kHz is at 800kw (which is actually more than all three Radio 4 longwave transmitters combined), which is probably the same as when it was broadcasting France Inter, so it doesn't seem like data alone uses a lower power signal.

If it's not going to cost any less to run the transmitters with just data, and the data is vital, maybe there should be some agreement over spitting costs between the different agencies.