A comprehensive quantification of biodiversity in farming systems would require a very significant amount of work (and funds) even for a small area. Therefore, biodiversity indicators are needed to solve the problem of the measurement feasibility. Even though the issue of cost and effectiveness is central for the evaluation of the indicators, only the latter is discussed in detail in the scientific literature. This work presents a cost analysis based on the direct gathering of records from a farm-scale biodiversity survey (EU-FP7, BioBio - “Indicators for biodiversity in organic and low-input farming systems”) where the analysis of costs is part of the project. It is a simple method for comparing different indicators by their ratio of cost/effectiveness. Here we present the results from the French case study (Gascony Hills, Midi-Pyrenees Region).