What we do is look at your address and perform a "Comparative Market Analysis". Basically, we look at recent sales of similar lots in your area and use those as a measuring stick for your land's value. Once we have the basics of your local market down, we can extrapolate the values. For example, if we know that vacant lots around 150 acres have sold for around $4000/acre, we can answer the question "How much is 200 acres of land worth?" It varies greatly depending on area and time.