I've just done salary negotiations myself. If you are going from A$100k to HK$1.1m that sounds about right; its about the same ratio as my "conversion".
Bear in mind if they are working it out in AUD that the dollar is super high right now; not to say it won't stay there or increase but historically it tends to be a 5-6 HKD instead of 8.
I sat down and did a spreadsheet trying to assess what I live on in Australia and what expenses are likely to be in HK. Some things are less, some are more. A good site is numbeo.com; you can compare the relative cost of living in any two cities.