This paper examines methods by which the efficiency of Project-Based Learning experiences can be quantified. One specific area of interest is the cost per student per project as a function of the number of learning outcomes for that project. The paper uses four Project-Based Learning experiences that have been offered to two different groups of students over the past two years as a test-bed for the investigation. Although quantitative results still need to be processed, instructor observations, project economics and student comments reveal that more significant learning outcomes are achieved when a project is both technically challenging and the technology is observable. For the projects examined in this investigation the more expensive projects were found to result in the more significant learning outcomes.