However, if one is only making 400 yuan a month, while it's certainly going to stretch further than it would in the developed world, it leaves very little left over for savings, and hence upward mobility, or any kind of mobility at all for that matter. If you need healthcare you are at the mercy of the limited facilities provided by the government, and if you end up in the hospital you'll be getting your own food (unless you have relatives or friends who will bring it to you). Your health-care will probably be something along the lines of 'injections' which they will give you for a while and hope you get better. If you get worse you can't afford decent health care (from a private provider or by greasing the right palms) so you either stay sick or die.
The average salary of urban workers (according to government statistics) is 18,000 yuan. These people are making considerably less, and, it should be mentioned, many of them are doing it outside of traditional safety zones of family and community. Many of these workers are migrant workers (who may not even 'exist' legally) from the provinces who have very little contact with family, and in the event of an emergency- such as a hospital stay- cannot fall back upon normal means of coping.