Buying a house may be one of most people's life goals.
As far as the possibility is concerned, you can afford a house by setting up a stall.
However, judging from the current social development, it is not easy to make efforts, opportunities and efforts from setting up a stall to buying a house. Success lies in a few. Influenced by class ideology, people say that it is difficult to afford a house by setting up a stall.
Back to what you said, someone successfully bought a house in the street, which reflects what kind of efforts he has made, the opportunities and conditions corresponding to his time and environment, and the comprehensive factors of his own qualities.
What the teacher means is that this road is extremely difficult, especially in today's times. When you have a choice, people will suggest choosing the best way.