Your purchase notes
Keep the details in one place.
Compare the producer, expression and volume together. Check whether the price includes a presentation box or other packaging.
A miniature and a standard bottle can share most of their name. Keep volume and pack count beside the expression so they cannot be mistaken for equivalent offers.
Compare the cost per unit
Choose one consistent unit: pieces, kilograms, litres or prepared litres, as appropriate. Divide total cost by the quantity. Do not compare unlike product types on price alone.