Expenses?
My water bill for last month totalled HK$38, electricity HK$288, phone HK$200 pcm which includes 10gig data (pay as you go, intl roaming not incl).
Rental 13k for a beautiful shoebox (400sq m) in Soho. You are out most of the time so not much more is required (for me at least).
The going out and drinking gets you.... If you didn't drink you'd be able to save heaps - by why on earth would you want to do that?? It's Hong Kong, live the 'dream'....