The seller is sad and the buyer is happy.
Sometimes the seller is saddened to have to sell a certain possession that is dear to his heart, and the buyer is happy at the time of its purchase.
("Come and see that the measure of the Holy One, blessed be He, is not the measure of flesh and blood, the measure of flesh and blood - a man sells a thing to his friend, sells sorrow and takes joy; but the Holy One, blessed be He, is not so - He gave them a law to Israel and joy, as it is said: For I have given you a good thing; do not forsake My law" - Blessings 5:1)
Translation
Expression (Hebrew)
הַמּוֹכֵר עָצוּב וְהַקּוֹנֶה שָׂמֵחַ
Definition (Hebrew)
לְעִתִּים הַמּוֹכֵר נֶעֱצַב שֶׁעָלָיו לִמְכֹּר נֶכֶס מְסֻיָּם הַיָּקָר לְלִבּוֹ וְהַקּוֹנֶה שָׂמַח בְּעֵת רְכִישָׁתוֹ.
("בֹּא וּרְאֵה שֶׁלֹּא כְּמִדַּת הַקָּדוֹשׁ בָּרוּךְ הוּא מִדַּת בָּשָׂר וָדָם, מִדַּת בָּשָׂר וָדָם - אָדָם מוֹכֵר חֵפֶץ לַחֲבֵרוֹ, מוֹכֵר עָצֵב וְלוֹקֵחַ שָׂמֵחַ; אֲבָל הַקָּדוֹשׁ בָּרוּךְ הוּא אֵינוֹ כֵּן - נָתַן לָהֶם תּוֹרָה לְיִשְׂרָאֵל וְשָׂמַח, שֶׁנֶּאֱמַר: כִּי לֶקַח טוֹב נָתַתִּי לָכֶם תּוֹרָתִי אַל תַּעֲזֹבוּ"- בְּרָכוֹת ה ע"א)