Price increases can be attributed in some respects to the rising price in fuel costs. It takes fuel to plant, harvest, process, and ship said item. Companies are doing whatever they can to hold their margins stable in order to keep the stockholders pacified.
Did see a report on tv (forgot where) where studies are now showing that the quick change to agri-fuel has greatly impacted food costs. This is due to farmers not keeping the food supply planting at the same amount and then growing additional crops for fuel.