Mishnayos Eruchin Perek 3 Mishnah 1

There are halakhot with regard to valuations that are lenient and others that are stringent; and there are halakhot with regard to an ancestral field that are lenient and others that are stringent; and there are halakhot with regard to a forewarned ox that killed a Canaanite slave that are lenient and others that are stringent; and there are halakhot with regard to a rapist, and a seducer, and a defamer that are lenient and others that are stringent. There are halakhot with regard to valuations that are lenient and others that are stringent; how so? Both in the case of one who took a vow of valuation to donate the fixed value of the most attractive among the Jewish people and in the case of one who took a vow of valuation to donate the fixed value of the most unsightly among the Jewish people, he gives the fixed payment of fifty sela, shekels, to the Temple treasury (see Leviticus 27:3). And if one said: It is incumbent upon me to donate the assessment of another to the Temple treasury, he gives the price for that person if sold as a slave, a sum that can be more or less than fifty shekels.

יֵשׁ בָּעֲרָכִין לְהָקֵל וּלְהַחֲמִיר, בִּשְׂדֵה אֲחֻזָּה לְהָקֵל וּלְהַחֲמִיר, בְּשׁוֹר הַמּוּעָד שֶׁהֵמִית אֶת הָעֶבֶד לְהָקֵל וּלְהַחֲמִיר, בָּאוֹנֵס וּבַמְּפַתֶּה וּבַמּוֹצִיא שֵׁם רָע לְהָקֵל וּלְהַחֲמִיר. יֵשׁ בָּעֲרָכִין לְהָקֵל וּלְהַחֲמִיר. כֵּיצַד. אֶחָד שֶׁהֶעֱרִיךְ אֶת הַנָּאֶה שֶׁבְּיִשְׂרָאֵל וְאֶת הַכָּעוּר שֶׁבְּיִשְׂרָאֵל, נוֹתֵן חֲמִשִּׁים סָלַע. וְאִם אָמַר הֲרֵי דָמָיו עָלָי, נוֹתֵן אֶת שָׁוְיוֹ: