This paper analyses the varied socio-economic implications of ICT-based educational change. Drawing from a rich, 3-year long research project with 20 secondary schools throughout Europe, the social, human, professional, institutional, and economic costs for building the school of tomorrow in close alliance with ICT are discussed. The aim of this paper is to show the "real costs" involved in such a comprehensive model of educational change, which cannot be reduced to the cost of installing computers in classrooms. Rather, it must aim at capturing the varied long-term requirements necessary for educational change in conjunction with ICT. Great emphasis is placed on questions concerning the very sustainability of innovation and the necessity to adopt a long-term perspective that provides us with a realistic socio-economic evaluation. We argue that the real costs of educational change only become apparent when short-term improvements have been converted into sustainable changes that last beyond a project's life-time. Key aspects for lasting contributions are identified, among which "network building" and applying a "bottom-up strategy" for change are given particular importance.