Not in defence of gouging and outrageous markup though but sometimes the product is no different but there's an added layer that adds cost.
By way of example. The sugar industry produces pure white sugar. Pure as in 99.9 odd %. This is the stuff that you put on your cereal and in your tea.
This purity will meet Pharmaceutical grade requirements (for making cough medicines and the like) but further testing is required to show that it is really absent from heavy metals, certain bacteria and other unpleasantness. Add in this and traceability and the price goes up relative to a 1kg packet of Silver Spoon on the shelf at Morrisons.
Are any sectors paying extra for added "peace of mind" in way of certification and warranties ?