Leviticus 27:12 KJV

10He shall not alter it, nor change it, a good for a bad, or a bad for a good: and if he shall at all change beast for beast, then it and the exchange thereof shall be holy.

11And 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:

12And the priest shall value it, whether it be good or bad: as thou valuest it, who art the priest, so shall it be.

13But if he will at all redeem it, then he shall add a fifth part thereof unto thy estimation.

14And when a man shall sanctify his house to be holy unto the LORD, then the priest shall estimate it, whether it be good or bad: as the priest shall estimate it, so shall it stand.