fibbi

A few things to consider:
Place to stay-do you have a place to stay in HK? You need to pay rent? Assuming you live with family here, so you don't need to pay rent here vs you need to pay rent in HK? Plus...room size is significantly smaller in HK...
Career path-depends on what you do, some jobs are easier to find in HK I guess? like advertising, design, PR? Maybe banking too? But for sure, be prepared much longer working hour and many jobs requires travelling to China...
Living standard: expense-wise...in your example, you say dine-out in Van is expensive than HK, well yes and no...yes that you can find cheap "fish ball noodle" in HK, so if you can live with "maxim", "wonton noodle" everyday, you can save $ on food. But in HK, most people like to stay in the "trend" and buy lots of gadget. Can you "resist" these "trends". If not...it's way easier to spend than save in HK...