Amid the widespread hunger crisis in Gaza, many Palestinians in the enclave have chosen to avoid aid sites and trucks carrying food, fearing they could be trampled or killed by gunfire. Instead, they have prioritized buying what food they can from the small number of markets and shops that still operate in the territory.

But finding enough money to buy food in Gaza is difficult because of an extreme shortage of hard cash itself. Banks and A.T.M.s have been destroyed and shut down, and since the Hamas-led attacks on Oct. 7, 2023, Israel has not allowed any large injections of physical cash by the banking sector into the enclave. That has opened up a black market for obtaining Israeli shekels, the predominant currency, with Palestinians forced to pay exorbitant rates to gain access to their money to feed themselves and their families.

At the same time, there has been a huge surge in the price of basic goods since the start of the war, especially in the face of Israeli restrictions on the entry of food into the territory. A 55-pound sack of flour is around $180, two pounds of sugar is about $10, and a similar amount of tomatoes about $20, according to surveys carried out this week by the Gaza Governorate Chamber of Commerce in three cities. Prices have come down since more goods have entered in recent days, but they are still far higher than before the war.

Some Palestinians have taken to selling their belongings. Some urge friends and family overseas to send funds. But even Palestinians with money in their bank accounts, including those receiving regular salaries from international organizations, are paying commissions of roughly 50 percent to people who have stockpiles of Israeli shekel notes for access to their own cash.

Those people — who are essentially using the cash they previously accumulated to make more money — have typically set up shop at internet cafes or on street corners in Gaza City, Deir al Balah and Khan Younis. They, or their representatives, offer bank notes to customers who then transfer funds online in exchange, according to residents of Gaza who use the system.