Hi Nalin,
Please check what type of Accommodation, If you are single may be request, well secured fully serviced apartment ,close to the office in POM. Best Salary would be $120,000,(AUD) but depend on your experience and qualifications.
Air fares to Sydney is it once a year, if so may be negotiate twice a year. How many days off I do not go clubbing, but jogging will not cost money. Estimate maximum AUD $ 100 for food per week,simple life style.
Dining out every day will cost you a fortune. Depends on how you live. $ 70, does not mean you are stuck with it for three years. Offer is somewhat reasonable.Acceptance is your decision.
Manel