I guess, I should speak to my experiences only.
My mother alone, as a cleaning lady, was fully supporting me on 30 000 salary in Belgium, Leuven. But as a cleaning lady, earning that money was not easy, or stress free. She was doing 50-60 hours weeks. I know cleaning ladies, my mother colleagues, who as a single mother support their kids and sometimes even manage to spare some money to send back home. I know that there are also people exploiting western social programs to the extend that they manage to live exclusively on child support. My mother has a neighbor who was laughing that she is silly to work, because she has Belgian fiancée and she should live off social support. And, yes, this type of people should be deported in my opinion.
Right now, I'm studying now in Maastricht, Netherlands and I work 1 day a week earning 8k gross a year. I'm living with my fiancée in apartment with one bedroom and I spent around 10k a year.