Answer:
Della is upset at the beginning of the story, because she did not have enough money to buy her husband, <em>Mr. James Dillingham Young</em>, a Christmas Present. As stated, "One dollar and eight-seven cents...", it can infer that they are:
1) Poor, to the point of poverty
2) Money is tight, and they have little to spare for extra condiments
3) Their marriage was not built on monetary value, but on love.
This leads Della to look for ways in which she can buy James his coveted watch chain. Now before we continue, we must note that in paragraph (11), it is noted that the "two [most prized] possessions... [are] Jim's gold watch... [and] Della's hair." Later on, you will follow Della, as she sells her prized possession (her hair), to buy James the watch chain that he wanted.
We continue to the climax as Della waits impatiently for James to come home, and when he comes home, Della is happy, but is stunned when James looks at her weird. Soon we find out why James was sad, in that he bought combs for Della, and that with her prized possession gone, she could not use it straight away. On the other hand, Della is surprised, because James sold his prized possession (his watch), to obtain the gift for Della. In the end, we can see that there is a theme of love and selflessness, and that one, in which giving away all, gains all.
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