In Kate Chopin's "A Pair of Silk Stockings," the protagonist Mrs. Sommers finds $5 and initially plans to spend the money on clothing for her children. However, when she goes out shopping, Mrs. Sommers is torn between fulfilling her assumed role as a good mother and her inner desires for freedom and individuality. Her family has little extra money, so Mrs. Sommers has always put her children before herself. But this time she cannot remain confined to the strict role of motherhood into which she has been cast. Mrs. Sommers is motivated to go on a shopping spree by her inner desire to express her individuality--she is tired of thinking of others before herself and never doing what is in her best interest alone. The shopping spree is a symbol for freedome and expression.
Mrs. Sommers's shopping spree seems to be motivated, at first, by a desire for something beautiful, to have something just for herself. She initially considers what would be the "proper and judicious" use of her funds, which seems to be the choice she must always make (with several children at home); however, she is lured by the temptation of the silk stockings. Her first purchase comes about as a result of the luxurious feel of something that Mrs. Sommers has not had in a long time. Moreover, they're on sale and there are several pairs in her size, and this makes it easier for her to take the first step.
Further, the fact that her neighbors sometimes talk of the "'better days'" Mrs. Sommers had before she became Mrs. Sommers helps us to understand that she has not always had to deny herself, that the specter of the "gaunt monster" of the future (which we can read to be poverty) is something to which she's had to become accustomed. Her spree, then, also seems motivated by a need to escape her present situation, an interpretation that is supported by the fact that Mrs. Sommers goes to a theater matinee (an escape from reality) and that she half wishes that the cable car she takes home would just keep going forever. She seems exhausted by the constant need to be careful -- to be judicious with her money at all times -- and she wants a day where she does not have to count her pennies and think of her children's needs first. In other words, Mrs. Sommers also wants to be selfish, just for a while.