A predatory transaction is one in which one party forces the other to transfer his or her interests (including the transfer of his or her goods) on the basis of coercion.
not a predatory transaction?
Zhang set up a grocery store. One day, a person came to buy a plastic basin, she took out one yuan to zhang said: I know a plastic basin price is 3 yuan, we are neighbors, the price is one yuan. And then took away the basin.