Levítico 27:12 Midrash: Sifra

2) "unclean": to include (in redemption) a dead (literally unclean) beast which he consecrated (for its money value). I might think that (it is redeemed) even if he said "This beast is consecrated" and (then) it died; it is, therefore, written "then the beast shall be stood … (Vayikra 27:12) and the Cohein shall valuate it." Where there is "standing," there is valuation; where there is no standing, there is no valuation.

6) (Vayikra 27:12) ("And the Cohein shall valuate it, good or bad. As the Cohein valuates it for you, so shall it be.") "And the Cohein shall valuate it, good or bad.": Consecrated animals are not redeemed by approximation, (but there must be an exact estimate). "As the Cohein valuates it for you, so shall it be": If one said: I will take it for ten selaim; another: for twenty; another: for thirty; another: for forty; another: for fifty — If the "fifty" backed out, his property is attached for ten selaim; if the "forty," his property is attached for ten; if the "thirty," his property is attached for ten; if the "twenty," his property is attached for ten; if the "ten," the animal is sold for its (market) worth, and the balance is made up by the "ten."

7) (Vayikra 27:13) "And if he would redeem, redeem it": to include one's heir. "then he shall add its fifth to your valuations": There are two (valuations) here (Vayikra 27 verse 12 and Vayikra 27 verse 13), one that adds a fifth (Vayikra 27 verse 13) and one that does not add a fifth (Vayikra 27 verse 12), and it is not known whether the owner or other men are being referred to. Just as we find in the "redemptions" mentioned below, the owner adds a fifth, but not other men (who wish to purchase it), so, in the "redemptions" mentioned here, the owner adds a fifth, and not other men.