Abstract:The key factors for a successful smart-city project are its initial cost and its scalability. The initial cost depends on several inter-related aspects that cannot be designed and optimized separately. After the pilot deployment, scaling-up takes place only if the cost remains affordable: an initial financial support may induce dependencies from technologies that become unsustainable in the long period. In addition, the initial adoption of an emerging technology that fails to affirm may jeopardize investment return. This paper investigates a smart-village use case, the success of which strongly depends on the initial cost and scalability, exploring a low-cost way for Internet of Things (IoT). We propose a simple conceptual framework for cost evaluation, and we verify its effectiveness with an exhaustive use case: a prototype sensor designed and tested with its surrounding eco-system. Using experimental results, we can estimate both performance and cost for a pilot system made of fifty sensors deployed in an urban area. We show that such cost grows linearly with system size, taking advantage of widely adopted technologies. The code and the design of the prototype are available, so that all steps are reproducible.