I guess everything relates back to the American Dream....

 Using your hard-earned money to buy a house is something you can do to prove to yourself that you have indeed succeeded in life and that the American Dream is coming true. This is why Mama from A Raisin in the Sun first suggests buying a house when talking about what to do with Walter Young's insurance money: "Been thinking that we maybe could meet the notes on a little old two-story somewhere." However, this was purely speculation on Mama's part because she never mentioned buying a house again. Part of this reason was because I think she knows the difficulty of acquiring a house due to severe housing discrimination during that time. She also mentions how she and Walter had similar dreams in the past and how they were going to "set away" and "buy a little place out in Morgan Park." Given Mama's characterization as a strong and independent woman, she has definitely tried to make her dream a reality. But there were many barriers in place to stop African-Americans from buying houses, such as price discrimination and social pressures. This is similar to The Great Gatsby, where the difficulty of making the American Dream come true was shown in acquiring wealth; whereas in this book, it is shown in housing and the difficulty of getting adequate housing. The fact that she has had this dream for such a long time, but has never achieved that dream goes to show how difficult it is to succeed and fulfill the American Dream.