COGS counts only the stock that left in orders, at the landed cost of the batches it came from. It is the number your accountant needs, and the one that tells you what your sales really earned.
Cost of goods sold (COGS)
The cost of the stock you actually sold in a period, used to work out gross margin.
See it running on your own catalog
Purity does the work these terms describe: batches held until their lab report is in, payments matched to orders, and wording checked before it sends.