Purpose: The aim of this study is to extend previous research on conceptions of price by highlighting variation in students' understanding of causality. It also aims to offer a new way of using 'dimensions of variation' in phenomenographic research to analyse the structure of conceptions of complex phenomena. Method: The study uses data from 94 upper secondary students who were asked to provide written answers to two problems before and after a short programme of teaching. This yielded a total of 328 open responses which were analysed phenomenographically. Findings: The study revealed four qualitatively distinct ways of understanding causation in pricing. It also revealed new insights in how different dimensions of variation in conceptions of pricing are related to each other. The study suggests that the form of a problem posed to students will affect the dimensions of variation in conceptions that are exposed. Implications: Conclusions drawn are relevant for research and teaching.