Hong Kong is a great place to visit or live short term. However, if you plan to stay for some duration, it is best to be making good money. Most expats that stick around, do so because they have better opportunities and make more money here than they could at home. I have a lot of friends who make double or triple what could back home...and that is the real reason they are still here.
Hong Kong is a very interesting, fun and easy place for expats to live. I jokingly call it 'Asia Light'. It is nothing like moving to Vietnam or Cambodia or even China. If you are thinking of living overseas..Hong Kong is certainly a good starting point.
Be warned, after the initial excitement wears off in a year or two, you will come to grips with the massive crowds, small,noisy cramped living conditions, horrendous air quality and perhaps the distance from friends and loved ones back home. This is where $$$$ comes into play. Having a good job with good pay can help overcome a lot of the perceived drawbacks to Hong Kong. Honestly, I don't think I could still be here if I was on a teachers salary...but than again, I know teachers here that make twice as much as they would back home, so actually some teachers are here for the money as well.
I am glad I came and have enjoyed it. I would do it again in a heartbeat. I would even consider living here long term if not for the lack of clean air, clean beaches, clean waterways. Once I reach my financial goals, I intend to more to greener pastures (literally).