Leviticus 27:8

27:8 If he is too poor to pay the conversion value, he must stand the person before the priest and the priest will establish his conversion value; according to what the man who made the vow can afford, the priest will establish his conversion value.

Leviticus 27:12

27:12 and the priest will establish its conversion value, whether good or bad. According to the assessed conversion value of the priest, thus it will be.