Hello there, JS87.

Let me share more details about the cost and average cost that don't match in QuickBooks.

In this case, the Cost and Average Cost don't usually match since the total cost means the sum of all costs, including fixed and variable costs. The Average cost is calculated by dividing the total cost of goods available by the total items available for sale. 

Additionally, QuickBooks posts the current average cost to COGS when you sell items that you do not have in stock. It then compares these costs to the average cost used when you sell items you purchase, and if there is a discrepancy, QuickBooks makes an adjustment entry to both COGS and inventory assets. For additional information on calculating average cost and reports that are useful for inventory management, see Understanding Inventory Assets and Cost of Goods Sold Tracking.

Let me know in the comment section if you need more help in accomplishing your other QuickBooks tasks. I'll be right here to keep assisting.