According to the old saw, economists know the price of everything and the value of nothing. Since price and value are synonyms, the real point of the saying is that economists can price materials objects, but they can’t price feelings, like love.
As a dismal scientist, I have to object. We all can and do price love and other feelings on a routine basis. Unfortunately, we have to do this when it comes to making decisions like staying married or getting divorced that involve our emotions as well as our feelings.