Kommentar zu Wajikra 27:12

כערכך הכהן כן יהיה AS THE PRIEST VALUES IT, SO SHALL IT BE for any other person who comes to buy it from the Temple treasury (in contrast to the owner himself who, if he redeems it, must add a fifth to the valuation, as stated in the next verse).

For other people who come to buy it from Temple property. Rashi is answering the question: Initially it is written “As the kohein determines its value for you, so shall it be,” but then [in the next verse] it is written “If he will indeed redeem it he shall add on one fifth to its valuation”? Rashi answers: Here it is speaking of another person who comes to buy it, and there [in the next verse it is speaking] of owners who want to redeem it. Gur Aryeh explains: But [here it is not speaking of] the owners, because the owners [who redeem it] have to add a fifth. You might ask: Just because it belonged to him before [why does] he haves to add a fifth? The explanation is that because it was his before, he is more satisfied [when he purchases it back], as it states everywhere (e.g., Bava Metzia 93b), “The difference [between keeping one’s own animals or having to buy new ones] is that his animals are accustomed to work for their owner, [i.e., it is easier for the owner to work with such animals].” Explanation:, a person prefers his first animal. Therefore, he has to add, because it is worth more to him. And the same applies to one who sanctifies his house. However, we still need to understand, why a fifth. According to teachings of wisdom, a second is not considered an addition to one, and a third is not considered an addition to two, and a fourth is not considered an addition to three. This is because [only] a plane is considered a complete [entity] as it has four corners. Therefore, a fourth portion is not considered an addition. But a fifth portion is considered an addition because a complete item is four. Therefore, one has to add a fifth portion.

Whether it is good or bad. He should appraise it specifically according to its worth, and not add to its value for the benefit of the Temple treasury.

As the kohein determines its value for you so shall it be. Nevertheless, if the kohein erred and did not appraise it according to its real worth — as he determined the value, so shall it be.