The only legitimate transaction is one in which the terms are agreed to by the buyer and seller. If a community (people other than the property owner) can subjectively assess property values and then seize the property then the concept of private property is meaningless.
Getting warmer. You can buy real estate and sell it. To that extend, you can own real estate. But it comes down to who has the ultimate power to use and dispose of land, and that is the public. You, of course, are not the public, nor do you represent the public. The public is those worthies you elect now and then as custodians of the public sector. Mayor, Councilmen, etc. And when their term is up, they return to the private sector and become just another private citizen. It's amazing we don't pay more attention to who we elect.