We used data on 174 land purchases to estimate two aspects of opportunity costs across Western Cape Province, South Africa; (i) that of complete loss (acquisition cost), and (ii) and partial loss of benefits of land ownership, the latter due to biodiversity-friendly management on potentially arable private land. Observed land prices varied by more than four orders of magnitude (from $US 15.ha-1 to 178,000.ha-1 per unit area of farmland). Mean annual precipitation, percentage of untransformed land, property area, and topographic diversity were the most significant predictors of land price (R2=0.67). Modelled acquisition costs were highest in vegetation types previously classified (based on biological importance and degree of conversion) as Critically Endangered.