Amazon calculates a product’s star ratings using a machine learned model instead of a raw data average. The machine learned model takes into account factors including: the age of a review, helpfulness votes by customers and whether the reviews are from verified purchases.
I bought 30ml of the Sibu Seaberry Oil on iherb.com for less than $50au and it’s fantastic! No staining, absorbs beautifully, and works. This amazon product is too expensive for what you are getting. 5 stars for the oil, but 1 Star for value/money.