A techno-economic analysis of multi-stage stacked tray (MSST) solar still coupled with a solar collector through a heat exchanger has been developed, Various heat and mass transfer phenomena have been considered for evaluating its distillate output. The economic analysis takes into account capital and maintenance costs, and life of the system and estimates the cost of unit mass of distilled water (C-u). In order to appreciate the developed model, numerical calculations have been made to optimize different design parameters, namely number of stages, evaporation surface area and collector area corresponding to climate of Delhi, India. The effect of useful life of the distillation unit on the cost of unit mass of distilled water has also been discussed. The study also includes a discussion on the sensitivity of cost of unit mass of distilled water in reference to the useful life of distillation chamber, cost of solar collector and other associated parameters.