Re: price/quality of fresh food.
If you buy fresh (or packaged/processed) food in HK supermarkets - varieties or brands that you are familiar with - you will pay through the nose.
However, if you are willing to be adventurous and convert to some extent to the sort of food local people eat and get at local markets, you can feed a family very very reasonably. It's just a question of depriving the little brats of their revolting junk food.
This principle applies to housing, haircuts, and other commodities.