@cibomatto sir sayang naman kung di mo tanggapin ang invite. 2 years ka lang naman matatali sa South Australia, its not that bad considering mababa ang cost of living dyan compared to NSW even with the same salary level.
Maraming intending migrants that want to be in your position, lalo na ang daming news that Austalia is planning on cutting numbers down for migration, my two cents. As of now, 9-12 months ang processing for visa application, by July 2018, new reforms will be introduced.
End of the day, may invite ka na sa SA. Push your luck till April 10 kung gusto mo talaga magantay for NSW, but I do hope by April 10 you've made up your mind and ready to submit ka na sa SA instead of disposing of the chance just to wait for NSW.