From the following, determine the value of the closing stock using:

Feb 1 purchased 200 units @ ₦2.00 each
Feb 3 purchased 100 units @ ₦1.00 each
Feb 4 issued 120 units @ ₦2.00 each
Feb 5 purchased 50 units @ ₦3.00 each
Feb 6 issued 80 units @ ₦2.00 each
Feb 6 issued 20 units @ ₦1.00 each