Cadlecrap - how are you getting the grant?
Kerloch - will you be coming over on a 457 visa? If your employer offers salary sacrifice or FBT you can recover 50% of the costs of education, flights, laptops, professional memberships, phones, internet, somewhat randomly airline lounge plan memberships and some others which escape me at the moment. That helps and it's something that people don't know about.
What may have changed since you last looked at migration is the LAFHA, living away from home allowance which would have let you recover 50% of your rent and living costs. It really hurt when that was abolished!
If you are from the UK then there is a reciprocal health care agreement which means you are eligible for medicare and so you can access free health care. You will have to pay for prescriptions/dental/optical etc though. I have private health cover too as there is a tax if you don't have it which is greater than the cost of the cover IYKWIM.
I'm in Sydney and have found things getting increasingly expensive, especially with the loss of the LAFHA. I've adjusted by being more careful really, I've cut out things that are wasteful - for example my weekly grocery bill is around $150 and I don't really buy much processed or out of season food. I don't really buy "stuff" and I often find it's cheaper to shop in the UK and ship - M&S for example has free shipping to Australia and the book depository also ships free to Australia and can save about 50%.
You can take a look at house prices on www.domain.com.au to get an idea of costs. There's also another thread in Living Overseas where people in Australia outlined their monthly expenses.
Car ownership is expensive if you are here on a visa, your payments have to be structured within the visa term, so can be high. I managed without one for the first few years but then had to get one for the school run. Leasing used to be quite tax efficient but they've clamped down on that one too.
In considering whether to return to the UK I decided that we do have a better quality of life here. DD's school is amazing (albeit cripplingly expensive) and she has a great outdoor lifestyle (she sails twice a week, swims daily, has swim sqad training and diving lessons). We'll spend New Years Eve watching the fireworks on the beach and Christmas Day eating in the garden.