Bava Batra 91A

מהיפרכיא להיפרכיא.

from the northernmost province [mehiparkheya] of Eretz Yisrael to the southernmost province of Syria.

תנו רבנן: אין משתכרים בארץ ישראל בדברים שיש בהן חיי נפש, כגון: יינות, שמנים וסלתות.

A baraita states: One may not earn a profit in Eretz Yisrael by buying and reselling items that contain an element of basic sustenance, such as wines, oils, and flours, because this causes their price to rise. Rather, those who grow the produce should sell them in the markets, without recourse to a middleman.

אמרו עליו על רבי אלעזר בן עזריה, שהיה משתכר ביין ושמן. ביין ⁠– סבר לה כרבי יהודה; בשמן ⁠– באתריה דרבי אלעזר בן עזריה שכיח מישחא.

The rabbis said of R' Elazar ben Azarya that he would earn a profit through the sale of wine and oil. With regard to wine, he holds in accordance with the opinion of R' Yehuda ben Beteira, who says that it is permitted to export wine from Eretz Yisrael despite the fact that this causes it to become more expensive, as drinking wine leads to licentiousness. With regard to oil, in R' Elazar ben Azarya’s locale oil was common; consequently, there was no concern that its price would rise if it were not sold directly to the consumer.

תנו רבנן: אין משתכרין פעמים בביצים. אמר מרי בר מרי: פליגי בה רב ושמואל; חד אמר: על חד תרי. וחד אמר: תגר לתגרא.

A baraita states: One may not earn a profit twice from the sale of eggs. Mari bar Mari said: Rav and Shmuel disagree about the meaning of that statement. One said it means that the seller may not charge double the price he paid for the eggs. And one said that one merchant may not sell to another merchant; rather, the merchant who buys from the owner of the eggs must sell directly to the consumer.

תנו רבנן: מתריעין על פרקמטיא, ואפילו בשבת.

§ Apropos price fluctuations, the Talmud cites a baraita. A baraita states: A community sounds the alarm and gathers in public prayer for merchandise [perakmatya] whose price has dropped. And even on Shabbat it is permitted to cry and plead, even though one may not pray for his personal needs on Shabbat, as this hardship affects the entire public.