in those days when your friendly FSO gave traffic it wasn't even mentioned if it was VFR or IFR
It was a long time ago now, but I'm pretty sure we did.
Surely at least $600 k a year but more likely $1 million. 80% paid by Qantas and Virgin and the Internationals
So only a guess then. GA gets a service for only 20% of the cost. Not a bad bargain.