The 30-second answer
There is no single fair price for every honey variety. First compare products with similar floral source, origin, size, and documentation. Calculate cost per 100g as jar price divided by net grams, multiplied by 100; add displayed delivery charges and fees for the real total. A higher price does not prove quality, and a lower one does not prove adulteration. Know what you are paying for.
Compare net weight, not jar size
Two jars may look alike but contain different net amounts of honey. For calculation only: a 250g jar priced at 60 units of your currency costs 24 per 100g, while a 500g jar priced at 100 costs 20 per 100g. Compare in the same currency using the final amount, and exclude the glass jar or gift box from honey weight. These numbers teach the method; they are not a market price recommendation.