This chapter presents the results of studies carried out in Argentina that assessed people’s willingness to pay (WTP) and willingness to accept (WTA) for useful plants conservation using the Contingent Valuation Methodology (CVM) and Avoided Costs Method (ACM). The WTP of residents in rural areas in Santiago del Estero, Argentina was researched. In this study residents expressed that medicinal, aromatic and dye plants are very important to them. In different parts of the province of Santiago del Estero, 125 families in six small towns were surveyed obtaining values of Consumer Surplus (CS) of $19.67 and Variation Compensatory (VC) of $22.156 (at an exchange rate US $1 equivalent to $3.20). Regarding dye plants, 35 artisans in these communities were also surveyed using the same method, and they expressed a willingness to pay (WTP) equivalent to $555.29 per month to preserve such plants. This tradition has been passed down over many generations, which ensures the availability of a continuous flow of environmental services. The results expressed in monetary terms that show the importance that environmental services provided by native forests for rural communities.