As others have said retailers will charge what they believe the market will bear and maybe they believe that Fuji slide will command a higher price than Agfa? Maybe they believe consumers think: "Agfa slides, isn't that old technology and isn't Agfa out of business? Isn't Fuji king of slide film?
Originally Posted by Simonh82
It is the same train of thought that makes sellers believe that "Lomo afficionados" will pay almost anything for old and long since defunct film.
They may be right in both cases. I haven't any experience of Agfa slide film but if it is anything like Agfa Vista colour neg film then it may have a distinct and muted colour signature which can be attractive.
Maybe we are lucky that retailers stick to the price that they set on their websites or in their shops. If pricing was based on their knowledge of consumers' desires or calculated assumption that a particular consumer thought that say Fuji Provia was the only slide film worth having then just watch the price soar if each transaction was the equivalent of a middle east bazaar