Two brothers inherited one of the Hawaiian islands, Niihau, and have turned down all offers to sell including $1 billion from the U.S. government
According to the brothers
"I've spent eighteen years and more than $250,000 doing this work, and I estimate it would cost the government or environmental groups $10–20 million to create a comparable reserve. I've done all phases of it myself; scouting, seed collecting, seed germination, planting, transplanting, watering, growing, fencing, fertilizing, and insecticide spraying. In most environmental groups or botanical gardens, the work is highly compartmentalized. You get your plant scouts, your seed collectors, your nurserymen, and people on the grounds. They all have different duties, and their duties never change, so none of them has a broad overview of what's going on. They don't know what specific problems there are at various stages where you're trying to produce the plants"