It is very difficult to give You an answer to this question, as the location is small and will not have many real estate agencies. I would recommend to find any real estate agency in nearby Lagos de Moreno, and ask them to help You on that. They at least know where to ask.
Best would be You visit the area and make contact there with the locals, as they can help You and know who has to sell what.
To make an estimation, if the lot is not inside the village it should cost between 1 Dollar and 20 Dollar a square meter. Allways depending if it is land for agriculture or for buildings.