When students are unable to purchase a textbook because of rising prices and/or are unwilling to carry heavy textbooks, their education is compromised. Open educational resources (OERs) are gaining in popularity because they solve these problems by providing free study materials in electronic formats, but students from different backgrounds and situations are impacted by OER in different ways. The aim of this paper is to analyze the usefulness of OER materials for students who are majoring in engineering, as well as those whose majors are in another (non-engineering) field. The impact of OER materials on students of different financial statuses, is also investigated. For this purpose, two classes of a graduate-level risk management course taught by the same instructor were selected. One class followed a web-based interactive OER system, and the other class followed the traditional textbook method. A survey was developed and distributed to measure 19 aspects of students' perceptions towards the web-based interactive OER system, and multiple statistical methods were used to analyze the collected survey data. Students' grades were also collected to analyze their academic performance. It was concluded that students majoring in engineering and students with financial constraints had a significantly more positive attitude towards the implementation of electronic OER materials. Furthermore, it was concluded that up-to-date OER materials with integrated advances in the field attract engineering students; whereas, free and/or low-cost educational resources are very appealing for students with higher education loans. The findings of this study will enable universities and colleges to effectively allocate financial resources towards the development and implementation of the OER materials.