Leviticus 27:11-13

11If, however, it is any unclean animal of the kind which 1men do not present as an offering to the Lord, then he shall place the animal before the priest. 12The priest shall value it 2as either good or bad; as you, the priest, value it, so it shall be. 13But if he should ever wish to redeem it, then he shall add one-fifth of it to your valuation.