"Customers who would come and buy three chickens before are now only buying one," said the owner of a poultry shop in the middle-class Arya Shahr neighbourhood in western Tehran. "They simply cannot afford these prices. The cause is that chicken feed prices have risen by four-and-a-half times their previous level. Although the feed is produced in Iran, we also used imports but we can't do that now because sanctions mean we can no longer get letters of credit. That has caused the price of locally-produced feed to rise. Mismanagement, sanctions and profiteering are all playing a part."