Steps to correct the merchandise item cost:

Please note: Following these steps may skew your over-all reporting for cost of goods sold
  1. Go to the Merchandise section, select Merchandise search, and open the item you are wanting to change
  2. Note the inventory number of the Inventory tab and highlight the item
  3. Select Change inventory, mark the box to Adjust quantity, enter a negative value to reduce the inventory count to zero, add a custom Reason, and save this change
  4. Select Change inventory again, mark the box to Add inventory shipment, choose the correct cost and quantity and save this to successfully update the cost