Leviticus 27:11-13

And if {it be} any unclean beast, of which they do not offer a sacrifice unto the LORD, then he shall present the beast before the priest: And the priest shall value it, whether it be good or bad: as thou valuest it, {who art} the priest, so shall it be. {as...: Heb. according to thy estimation, O priest, etc} But if he will at all redeem it, then he shall add a fifth {part} thereof unto thy estimation.