Agreed the wages a year ago were higher, somewhat caused by some companies offering silly money.12 months ago, you would have been in a far stronger position to negotiate on the package.
The harsh fact is now that companies are not offering the packages they once were.
However, it would certainly be worth contacting them about schooling and housing allowances. They may well say that it is an all-inclusive monthly sum, but unless you ask the question.........
An item to note is while alot of people have lost thier jobs, Alot of good candidates have returned to thier home country, therefore there is less good competition for yourself. Definately worth Negociating.
I expect housing is included and schools. schooling is about 6k a term so 18 a year for each child + any bus fees. a 3/4 bedroom will set you back between 120-200k a year.