Well of course people are already shungry and looting supermarkets, the army on teh streets trying to keep control of the situation.
Most saught after items?
Candles (I suppose that battries/flashlights as well... but thats just my speculation)
Bread is selling for around 8 dollars per kilo, ATMs arent working and credit and debit cards arent being accepted.
The government has set up generator in the Plaza de Armas so that people can charge their cell phones.(get a solar/crank cell phone charger)
The situation is pretty complicated and havent heard from cousin and aunt since yesterday.
Notice how its always the same basics: water, food, shelter and lighting. Means of comunication. Money buys you stuff as long as you have cash. Medicines or supplies for babies or the sick.
There's a number of disasters and events that can be much better dealt with if you have some basic supplies at hand.