To dboy...if you have never been in Hong Kong...but you are going there for an interview, I would suggest you take a week there to look around, and try to find places to live, I mean a place to live that you would find acceptable. Then see how much of you "wonderful" 6400 euros you have left to spend on other things...like food.
There is no way on earth as an expat I would go to HKG without housing allowance. I do another expat gig, and there is no way I would stay where I am unless they gave me my house, or a big allowance. Being an expat, is not being at home, I repeat, is not being at home....so keep your eyes wide open and take it all in. And listen to what others are telling you.