Agree, but economists do have a solution for this problem. Self-assess the value and pay taxes based on that value. If someone/the government makes an offer that is some percentage greater than that value, you must sell.
Sounds like a solution only an econ could think up of, which doesn't take into consideration other external factors that would apply specifically to the person holding the property, such as:
- human psychology (loss aversion, endowment effect, mental anxiety due to risk of being forced to sell your property)
- switching costs (monetary, mental, time spent searching for alternatives, costs to moving to something else)
- replacement costs (transaction costs, etc)