Hi
This is on the low scale of wages however taking into consideration the lower tax rate that you will pay, your disposable income will be higher than in Australia. If your salary in negotiable you will want to try for additional:
Suggest taxi / transportation allowance
Suggest spouse entitlement allowance
Suggest child entitlement allowance
Joining fee of Australia club for the family
Insurance - medical/travel included as well (very expensive for medical in Singapore) for the whole family.
Home leave tickets - for you and family.
If you need schooling, you would want to have this included in your package.
Cars are not needed here as MRT is efficient and easy. Taxis are cheap as well.
Food and Groceries are expensive in Singapore as it is flown in. Alcohol as well, on average a beer will cost $10.00
On the rental allowance this is the average rate and you will be able to get a nice 3 bedroom apartment close to amenities etc. Suggest areas like Queenstown, Queens
condo 2.4K a month - MRT right at door, close to Orchard rd Tanglin mall etc. Holland Village another area...no MRT buses thought.