You could get the assessment at a university service, they use psych students so it is a bit cheaper.

The krongold centre at Monash Clayton, or Swinburne uni also has a clinic.

It it really needs to be an exceptional child for the ed department in victoria to accept early entry, and try to be reassured that if she's not assessed as gifted, the teachers are still expected to modify and stretch the curriculum to provide it at an apprproately challenging level.