Livng in Hongkong and how much you can save?

Hi

I will be given an offer to relocate to HK but I have no idea about cost of living in HK.

I wish to know what is the avg sal one should earn to sustain a family of 4 (including one infant)? 
Office is in Tai Koo Shing area, so I would be looking for 2 bedroom house near that area only.

I also need a rough idea on food expense? I know it's totally dependent on what/where we eat... let say no eating out and no beer or drinks etc... if we prepare food at home, how much will it come up on a monthly basis for 3 members? a rough estimate would do.

Is 30K HKD p/m enough? What is the % HK govt deduct as tax?
How much can I expect to save p/m?

Regards,
M

I am interest to know someone who could help me to find how could I invest in appartment in Honk kong or other, what is the legislation for buy something there ? mERCI