What is the common circumstantial struggle faced by jim and della in “the gift of the magi” and federigo and monna in “federigo’s falcon”?

The common circumstantial struggle faced by the couples in both of these stories is that of poverty.

To be more specific, each lacks the money to give their beloved a worthy gift. Jim and Della do not have the money to buy good Christmas presents for one another, and Federico does not have the money to give Monna a good dinner. 

As a result, each makes sacrifices in order to give to their love. Being poor, however, is the struggle each initially faced.