Many thanks to all for such great advice!
Short update - my husb. was advised (by expat peers here in Miami) not to enter the expat package just yet, but to negotiate salary conditions first, then go into expat package in detail, with all our requirements.
For ref., currently we have a three bedroom house in Miami. We build a gorgeous little pool in our backyard, which is very tropical and luscious. The house is not considered 'luxurious' though, since it is pretty small (1,600 sq living space). We have two cars (necessity here in Miami) and we do not have extravagant tastes. Movie and dinner once in a while, dinner parties at friends house or ours more than anything else. We do like to take a trip to the caribbean in summer and skiing in winter, which is the only real indulgence we offer ourselves per year. I would say we live pretty much pay check to paycheck but we are comfortable and most importantly happy with our quality of life.
Now here's my question: would 780K HKD ($100,000 USD) gross per year be enough for living expenses?
Considering that currently we are on a $130K USD/year gross income (both our salaries), after taxes and annual mortgage deduction, we are at a total of $70 K net per year. Which is what I think we would be left with in HK (if we obtain 780K per year) after US and HK taxes.
All this ofcourse considering that we plan on negotiating 60K per month of housing allowance (obviously not a house with a pool but at least a 1,600 sqf. 3 bedroom appartment with hopefully a pool in the complex, in a nice area), tuition for both our sons, bus. trip home once per year, moving, settling-in and repatriation costs (thanks for your advice Dkcqu!).
Does the salary seem fair? Are we aiming too short or high or are our calculations realistic?
As a reminder, my husb. is French working for a major French cosmetics company and would be transferred to be head of department (which he currently is he is here in Miami, responsible of the Americas market). As for me, I work for a major French luxury brand, but I do not want to take this in consideration, as I have not yet decided whether I want to work, at leat not yet (I might have the possibility of doing so at our HK branch).
Many thanks in advance for all information you may provide!