Rice, lentils, peas, beans, wheat berries, barley, oats, etc. But if you buy in large bulk (which you should do for the cost savings), you should repack the goods into smaller individually sealed containers. Because a 25kg bag of rice, once opened, will take a small family all year to get through, and having an open bag of rice attracts rodents, weevils, moisture, mould and dust. Pack it down into half kilo or 1kg containers, ideally vacuum sealed or with some other preventative treatment. Then only open 1 container at a time.

This is good advice not just for building resilience against food cost shocks, but just generally good practice for saving money by buying in bulk and repacking yourself. Around here,a 25kg bag of rice costs me about $40, but buying 25kgs of rice in individual kilo bags at the supermarket costs $3.50 per kilogram for the cheap stuff, or $7.50 for the premium stuff ($88 or $188 respectively for 25kg worth)