My god, have people forgotten what this housing allowance was for? Why guys are willing to come to Hong Kong without one is beyond me, unless you are single with 0 flying hours it is crazy. You are coming here to be a professional pilot, you should not have to get by, it should not be questions as to weather you can survive or will I be able to buy the things I do back home without going bankrupt!
It is all about comparable living to attract experience. As a professional pilot for BA or VS back home I could buy a 4 bedroom house near the city and live comfortably. In Hong Kong, even WITH the expat allowance this would be hard as this sort of property is anywhere from HK$15,000,000 up to whatever you can think depending on location.
If you join without expat benefits and are an expat you will spend you WHOLE career paying off some tiny flat next to the airport, lovely place to retire once the whole 800 sq/ft are all yours!
Yes you can survive on what they are offering but why the hell would you want to. I got into this profession so I could do more than survive, why people continue to enter it is a mystery.