A nation produces 500 units of output. It sells 400 of these to domestic consumers at a price of $2 per unit, and exports the remaining 100 units to countries overseas at a price of $2.50 per unit. The country also imports 50 units of another good at a price of $3 per unit. There is neither investment nor government expenditure in this economy. Aggregate demand for the output of this country is ______ .