Ok hopefully this will make you understand.
Someone leaves your town but they have an awesome house with lots of diamonds.
It goes up for sale at a price of 0 meebles.
As a mayor you might not see that the plot is for sale until someone has already bought it.
If the plot costs 100,000,000 meenles know one can buy it except for you and assistants.
do /plot fs 0 and then claim it!
Hope this helps :)
