Yerushalmi Mes’ Qiddushin (or, as the Y-mi would itself call it: Meikhas Qiddushin, see here , the section subtitled “Linguistics”, for why I believe the difference in nomenclature is significant) includes three discussions that I believe reflect on the topic of how to relate value to price.
In 2:5, vilna ed. 25a, the gemara discusses the possibility of marrying a woman not by giving her something worth at least a perutah, but by pardoning a loan. Something actually has to be given, though. It’s not sufficient to move money around on ledgers, as this is part of the pro forma of the wedding rite. So the gemara suggests that he is giving her an intangible — the value of the utility/enjoyment of not having to pay the loan back. If he tells her (romantic that he is) to repay the majority of the loan, leaving the rest to be pardoned to effect the marriage, Rav Shim’on ben Elazar quotes R’ Meir, who understandably says that a minimum of a perutah must be left of the loan in order for the marriage to take effect.
Rabbi Yosi disagrees. He suggests that one must leave more than a perutah to the loan. After all, “שמא נותן שוה פרוטה על שוה פרוטה”, would someone pay a perutah to be pardoned of a loan of a perutah? A pardon is worth less than the amount pardoned, because that is the only reasonable purchase price.
Second case is that of tovas hana’ah, the value of being able to pick which kohein to give one’s terumah to. (Or to give sections of his offering, or to pick a levi to receive his ma’aser, or….) The mishnah 2:9 (on 30b) says that a woman can be married by relinquishing that right to her. Rabbi Yosi explains that this utility/enjoyment (if of enough produce for the right itself to be worth more than a perutah) can get a gift for the purpose of marriage. Rabbi Yochanan disagrees with Rabbi Yosi, and says that tovas hana’ah has no market value. Say a man’s daughter married a kohein, so that he himself is not a kohein (a kohein can’t buy terumah, doing business in terumah is both prohibited and ineffective) but his grandson is. Even if the grandfather [aid the farmer for the right, he couldn’t compel the farmer to give his terumah to his grandson.
In the Yerushalmi’s version of the dispute, both sides believe in tovas hana’ah, but Rabbi Yosi says it has market value, and Rabbi Yochanan says it does not.
The third discussion is at 3:6 (37b). The topic is whether one can marry a woman by providing services rather than giving goods. The unnamed opinion in the gemara is that he can. Rabbi Ba (the Bavli’s R’ Abba) says that this is only true if she sets aside an actual sela coin to pay him, and he pardons the payment. The service itself isn’t a “thing” to be given, only the set aside coin would be.
Rabbi Yosi in the first two disputes takes the side that since we say something has value, it must have payment value. Tovas hana’ah exists, so there must be a way to pay for it. And the amount one would pay to pardon a loan is its assessed value.
Rabbi Ba appears to disagree with that basic proposition. (As did R’ Shimon ben Elazar’s tradition about Rav Meir’s position, and R’ Yochanan.) Something can be of value to someone without it being of financial value.
In the end, the majority of the amoraim of Eretz Yisrael hold “Money can’t buy happiness!”