The central message of the story is that love is more important than money, and this is an important message.
The story is a triumph of love over materialism. In the story, a young couple tries to give one another valuable presents for Christmas. Each sacrifices something important to give the other something. Unfortunately, Della sells her hair to get James a chain for his watch, and James sells his watch to buy Della combs for her hair. So ironically, each sells what he or she finds most valuable to give the other something that she or he finds most valuable.
When Jim comes home and sees Della has cut her hair, it comes as quite a shock to him.
I had my hair cut off and sold it because I couldn't have lived through Christmas without giving you a present. It'll grow out again—you won't mind, will you? I just had to do it.
The reason he is upset is not just because she had to cut her beautiful hair for him, which he feels bad about, but because his present becomes kind of worthless as a result. A comb won’t mean as much if she has nothing to comb.
The young couple realizes that they have something more important than anything money can buy, and the message is also valuable. You do not need money to be happy. All you need to be happy is love.
The central purpose of the story is to show the lengths people who love each other go to in order to make each other happy. It is a story two great sacrfices made by a husband and wife to purchsae each other meanigful gifts.