The document discusses what is currently known about the costs and benefits of institutional repositories. More is known about startup costs than ongoing costs, and more about theoretical benefits than practical benefits. It provides examples of repository costs from various studies and outlines factors that affect costs like staffing needs, content type, and potential economies of scale. It also stresses the need to quantify benefits in specific rather than general terms and potentially in financial terms to justify ongoing institutional support. Collecting long-term cost and benefit data tailored to each institution is important for making the case for continued repository funding.