Donors face increasing political pressures to demonstrate that their aid programmes are providing 'value for money' (VFM), the challenges in the evaluation process for market-supporting projects such as Financial Sector Deepining (FSD), Kenya is a matter of considerable concern. As this problem has more general significance, this working paper outlines the problem more fully and then uses the FSD Kenya case to elaborate a simple but pragmatic approach that illustrates one possible way to address this type of problem. The working paper also compares the overall costs and benefits of the FSD Kenya programme. The paper has explicitly stated all the assumptions that have been used, so that these can be subjected to closer scrutiny by other stakeholders, with the present paper being seen as an intermediate step to encourage better VFM analysis in the future.