The interaction between the money changer and the protagonist highlights a power imbalance.
The desperation to sell a high-value item for a fraction of its worth speaks to a systemic lack of social safety nets. Irony and Tone
It serves as a symbol of status and "time" as a luxury.
A watch is meant to help one manage the future, yet the protagonist must sell it just to survive the present.
While the watch marks hours in gold and precision, the characters are marking time in hunger and desperation.
The money changer acts as a gatekeeper, profiting from the misfortune of those forced to liquidate their few prized possessions.