Can Iran afford to keep firing so many missiles?

Iran fired almost 35 missiles and 110 drones every day at its Gulf neighbors before the ceasefire; that’s about 45 million dollars per day, or 1.3 billion dollars per month. For a country with only an estimated 11 billion in accessible foreign exchange reserves, that is a LOT of money to burn through. How long can Iran actually afford to keep fighting before its war economy collapses?