Donated! Direct land acquisition by nonprofits is the future of conservation. I did the math once, and with the annual budget of The Nature Conservancy, you could purchase 20% of Nebraska in a perfectly reasonable amount of time.
I am very proud to have been involved in the Nature Conservancy's effort to restore wetlands in Oregon. I completely agree that land acquisition is a great path forward, as long as the longevity of that acquisition can be secured.