I don't mean to make some grand moral claim about markets always being "just." My point is that a buyer who gets to force someone to sell AND gets to choose the

I don't mean to make some grand moral claim about markets always being "just." My point is that a buyer who gets to force someone to sell AND gets to choose the price they must sell at is VERY far from my intuitive (yet admittedly ill-defined) feelings about justice. In your example, it seems perfectly reasonable to me that one person may value their land much more than their 20 neighbors value their own lands. Perhaps the one plot of land has been in the family for generations and has immense sentimental value. Perhaps the one landowner doesn't approve of the development project being pursued.