Organizations in South Africa (SA) and other economically developing countries are not maximizing the use of Enterprise Resource Planning (ERP) Systems. While the costs associated with an ERP system implementation have always been a major factor to many organizations, Open Source Software (OSS) ERP systems are available offering the benefits of an ERP system at a reduced cost to organizations. This paper investigates the adoption factors of Open Source Software Enterprise Resource Planning Systems in economically developing countries by focusing on South African organizations. Using online surveys and a focus group discussion, this empirical study found that knowledge barriers, the lack of sizable providers (or vendors), and ironically low costs, are the adoption barriers that apply to OSS ERP systems for South African organizations. The research further suggests that many of the adoption barriers traditionally associated with OSS might be inherent to all software. The possibility of low costs being a barrier is a novel idea that was identified in this research, and further research to explore this idea is suggested. Understanding the dynamics of the market requirements is crucial for OSS ERP vendors to be able to develop effective strategies. OSS ERP vendors and OSS vendors in general can use this study as a starting point to question some traditionally held notions regarding the OSS business model.