Alice Springs may be closer to Perth and Adelaide although that doesn't qualify it as being an appropriate supplementary airport to Sydney as it is geographically one thousand times the distance from Sydney that Orange is.
The bulk of the $25M did come from the NSW Government through re-allocation out of other projects. This occurred because the current NSW Government does realise that NSW does not stand for "Sydney, Newcastle and Wollongong".
A high proportion of the funding was also allocated by Newcrest, a local Mining company. This was a result of Newcrest's need to facilitate high capacity aircraft into Orange for crew transfers.