Price per unit is a Shopify feature that is currently only available for merchants located in France or Germany.
The following elements must be enabled/set for the price to show:
- A store location set somewhere in France or Germany.
- Show unit price for this product is enabled for the product within Products.
- A price and measurement have been assigned, in the same space as the above.
- The product has no variants enabled - you may wish to offer a product with different variants as separated products, to ensure this all appears correctly.