DOWNWARD — In the 10 trading days since OPEC last met on December 4 and decided not to set any quota, the price of an OPEC barrel has dropped 17 percent. The price is still above $30; it was $31.63 last Friday. But First Vice President Es’haq Jahangiri last week said he expects it will drop below $30. In September, the government said it was devising the budget with three oil price assumptions—$42, $45 and $50.DOWNWARD — In the 10 trading days since OPEC last met on December 4 and decided not to set any quota, the price of an OPEC barrel has dropped 17 percent. The price is still above $30; it was $31.63 last Friday. But First Vice President Es’haq Jahangiri last week said he expects it will drop below $30. In September, the government said it was devising the budget with three oil price assumptions—$42, $45 and $50.