jiǎng jià yǒu lái yǒu huí gěi duì fāng liú tái jiē yě gěi zì jǐ liú chū kǒu

讲价有来有回，给对方留台阶，也给自己留出口。

Bargaining involves give and take; leave room for the other party, and also leave an out for yourself.