Shopify stores one cost per item, but purchase prices change with every order, so the recorded cost goes stale and your margins drift. True COGS fixes this at the source: when stock is received, enter what you paid and the cost is recalculated and written back instantly — weighted average or FIFO. Set every line of a shipment on one screen, and spread freight and duty for true landed cost. Every change is saved to a permanent history that is never overwritten, with CSV export.

• Detects every inventory receipt from purchase order transfers automatically
• Live weighted average preview as you type the cost you paid
• Writes the new average straight to Shopify's cost per item field
• Permanent cost history ledger — past averages are never overwritten
• Ask-me mode or auto-apply: you control how each receipt is costed