Bechoros8: 7
חָמֵשׁ סְלָעִים שֶׁל בֵּן — בְּמָנֶה צוֹרִי. שְׁלשִׁים שֶׁל עֶבֶד, וַחֲמִשִּׁים שֶׁל אוֹנֵס וְשֶׁל מְפַתֶּה, וּמֵאָה שֶׁל מוֹצִיא שֵׁם רָע — כֻּלָּם בְּשֶׁקֶל הַקֹּדֶשׁ, בְּמָנֶה צוֹרִי. וְכֻלָּם נִפְדִּין בְּכֶסֶף, וּבְשָׁוֶה כֶסֶף, חוּץ מִן הַשְּׁקָלִים.
The five selaim of the son are in the Tyrian maneh. The thirty [selaim] of the slave, the fifty of the violator and the seducer, the hundred of the one who defames [his wife] —- are all in the shekel of the Sanctuary, in the Tyrian maneh. All of them may be redeemed with money, or its equivalent, with the exception of the shekalim.
Bechoros8: 8
אֵין פּוֹדִין לֹא בַעֲבָדִים, וְלֹא בִשְׁטָרוֹת, וְלֹא בְקַרְקָעוֹת; וְלֹא בְהֶקְדֵּשׁוֹת. כָּתַב לַכֹּהֵן שֶׁהוּא חַיָּב לוֹ חָמֵשׁ סְלָעִים — חַיָּב לִיתֵּן לוֹ, וּבְנוֹ אֵינוֹ פָדוּי. לְפִיכָךְ, אִם רָצָה הַכֹּהֵן לִיתֵּן לוֹ מַתָּנָה — רַשַּׁאי.  הַמַּפְרִישׁ פִּדְיוֹן בְּנוֹ וְאָבַד — חַיָּב בְּאַחֲרָיוּתוֹ; שֶׁנֶּאֱמַר: ,,יִהְיֶה־לָּךְ” וּ,,פָּדֹה תִפְדֶּה”.
One may not redeem either with slaves, with [loan] documents, or with land; and [similarly] not in the case of consecrated objects. [If] he wrote to a Kohen that he owes him five selaim, he is obligated to give [them to] him, but his son is not redeemed. Therefore, if the Kohen wishes to give him a gift, he may.  [If] one sets aside [money for] the redemption of his son and it is lost, he is responsible for it; as it states (Num. 18:15): It shall be yours, and you shall redeem.