Piper is a business owner who is trying to determine their cost of goods sold for the current year. They bought $20$ units of inventory at $$11,$ then $26$ units at $$10,$ and finally $18$ units at $$14.$ They sold $30$ units at an average price of $$16$ per unit during the current year and used FIFO for their inventory valuation. What was their cost of goods sold in the current year, assuming that there was no inventory at the beginning of the year?

a$.$ $$732$

b$.$ $$480$

c$.$ $$330$

d$.$ $$320$