Kaboom, If there is nothing else in you package - US$3000/mth is all in, then stay away - stay along way away. For a package that will not subsidise housing or schooling - at a guess - I would say that US$5000+ would be your opening gambit - and even with that number you would be watching the pennies. Your biggest factor - and here I assume that you are a westener (ang moh), would be your kids education. Unfortunately the international school fees have run rampant and can constitute a huge portionof your salary. However if you go with local education, then it's almost free.
Having said that, if you can get enough of a package living in Sin to me, -is great.
Good luck and let us all know how it goes.