Rules

Applies only when the supplier's main (RRP) price is empty for a product, but a cost price is present — its own markup/rounding, calculated independently from the main Price calculation above.

Purely informational — writes the supplier's cost price (with the markup below, or none) into a custom field on the Woo product, so it's visible next to the retail price when someone's adjusting it later. This never changes the actual sell price — only the custom field. Only set when the supplier actually has a cost price for that specific product.