Be careful if you think he'll save on income tax. Unless you're truly none resident the ATO will still want it's cut and 26AG is long gone.
Hanni pretty much summed it up. For an Aussie family you can't expect not to have a drop in living standards mainly due to the small apartment sizes.... however here goes;
1. Schooling - 100% payment by the company - WHY? Because Schooling at good state schools in Australia is essentially free. If they don't pay - don't come. Seriously. It's the biggest issue for expats here and cannot be under estimated how much it can impact positively or negatively your experience.
2. Housing and Moving expenses - including 3 months in serviced accom and a minimum of 400 ft2 per person for the apartment. Anything else is very cramped. I'd suggest for you a 20ft container would be necessary to move all you need over AND back. If you buy furniture here it's a 100% loss when you leave unless you can ship it home FOC.
3. A leased car contribution of $1500 per month - why? Because it's around $2000 a month here and in Australia the same care is $500 a month lease.
4. Health insurance. Pretty much necessary as foreigners you won't have any access to Singapore's excellent subsidized health care without 100% payments and often up front.
5. Severance. Make sure you DH contract either contains continuity of service under the Australian entity or some other wording. I'd consider running this past an Australian lawyer. Also you need to think about Super -will it be paid while you're gone or 'topped up' on top of his salary while in Singapore? - that's 10% gone if it's not paid. Make sure his Long Service Leave is protected or acknowledged as well.
If you're giving up too much - don't come. If your DH employer doesn't want to do this (or most of it) don't come - nothing worse than an unprofessional expat package.
When you leave Australia consider;
1. Obtaining tax non resident status from the ATO
2. Obtaining a recess on your Australian private health care so you can resume it without penalty on your return (7 yr max I think).
3 Making sure your kids are on school enrollment lists for your return if they are going to an exclusive school.
4. Renting out your house via a
property manager (don't sell if you can help it - the closing and repurchase costs are significant losses).
