Translating maps of priority areas for conservation into activities which actually secure these places is a complex process, overwhelmingly influenced by human and social factors. Spatial conservation prioritizations often assume that land is available for acquisition. Using data gathered through interviews, we predicted land managers willingness-to-sell their land. We included this information in spatial prioritization analyses that aimed to identify areas that achieve conservation objectives while maximizing the probability that land will be available for acquisition. As anticipated, our solutions were more likely of being available for acquisition compared to solutions that did not include the willingness-to-sell data. Our results illustrate the trade-off between designing so-called "optimal" networks of protected areas, and the realities of translating these maps into on-ground action. We demonstrate how an important aspect of the social context in which conservation is embedded and defines conservation opportunities can be explicitly accounted for in the development of conservation plans.