I'm still too harsh. A GBAS system installed will be way too expensive to be of benefit to any aviation outside heavy iron or mil ops.
If it was my say so on provision of GPS infrastructure, I would take the same view as the US. GPS is an enabler of commerce, that is to say it returns far more to the economy than what it costs to run. Considering the expensive bit is already up there with the capability already operational, all that is required are the monitoring stations linked up to the reference uplink already in Canberra and we have WAAS over the entire continent via the MTSAT. Considering there is already 28 surveyed in ADS-B sites evenly distributed across the country...already talking to mummy...makes you just wonder about the possibilities for the nation in general. Considering the landing accidents over the years from non precision approaches in marginal wx, what cost is a life?
This argument has already been had. The Feds take a narrow view of cost recovery. We are never likely to see any government of any colour do such a thing ever again in this country.