Here is my two pennies worth:
If you want to come just for the experience then the amount of money you’ve been offered is plenty to live a comfortable life – many expats do on less. If your wife works too you should have plenty for savings too. It may or may not be comparable to what you have back home but if it’s something you both want to do for the adventure of it I don’t think you’ll lose out overall.
I’d echo the suggestions from others to come and try before you buy, Hong Kong is a wonderful place but it can be an assault on the senses and isn’t for everybody.
There are also a few universal truths that a few other people have already mentioned –where you live will be much smaller than you’re probably used to and the quality will most likely be shoddy in comparison.
Food costs are much higher than the UK and the quality is often poor – though with a bit of digging you can source good quality stuff for more reasonable prices, just keep in mind it’s not as simple as popping to Sainsburys. Tung Chung is actually a good place in this regard, there is a good butcher there, a great frozen meat store which delivers from nearby Mui Wo twice a week and well stocked Indian provisions store for some herbs and spices you may miss for example. I’d budget at least $2k+ per week if you are doing all your shopping at Jason’s or Taste (the two bigger expat supermarkets in Tung Chung.)
Tung Chung is a love/hate kind of place in my experience. Some people swear by the place and wouldn’t live anywhere else, others find it dull and isolated. The rents are very reasonable and many of the complexes have great facilities. You mentioned Caribbean Coast which is one of the larger developments, just keep in mind that it is situated with the airport on one side and a motorway on the other. Not trying to put you off but definitely go and have a look before you set your heart on it as it may not be everybody’s cup of tea. What it does have in its favour is the ease of access to both Central and greenery and beaches of Lantau, which are some of Hong Kong’s best spots to spend outdoors in my opinion. There are plenty of expats around so meeting people shouldn’t be an issue.
While you can feed a family of four in a restaurant for $400 you’ll find that figure is usually way higher, especially once you factor in booze. A beer here is usually between $60-$80 in a Western style restaurant (cheaper in Chinese places) plus you have to factor in a mandatory 10% service charge on everything. I usually find if I go out for a meal with my wife and kids it’s usually in the $800-$1000 range unless we are going something like dim sum, where we can all eat for under $150 sometimes depending on where we go. I know some others will say that my figures are off (another universal HK truth is that somebody will disagree with almost everything you say on Geoexpat!) but these are my experiences. What you’ll find is people you meet will suggest meeting in certain common places so even if you make an effort not to spend too much on eating out you’ll probably find your social life will force you to!
Schooling will be a priority to arrange for you as getting places is tricky and you may end up shelling out large sums of money and still not getting a place. There is a tonne of information that has been written on HK schools and how much of a pain in the arse getting a spot is so I won’t duplicate it here, but you should focus on getting that arranged before you decide where to live in my opinion. The local system is very much an option if you want to go down that route – my eldest has been attending a local kindergarten in Tung Chung for the past few years and will go to a local primary school next year. Me and my wife are Brits who speak zero Chinese at home so it is do-able. If you want to know more drop me a PM, I’d be happy to share my experiences on the process – both good and bad.
Hope this mini essay is helpful and I wish you guys all the best with the move if you decide to take the plunge!