הלכה על עבודה זרה 2:4

Nonetheless, Rav Weitman (Bin’tiv Hechalav p. 40) contends that since the price of non-kosher milk is tens of times greater than that of kosher milk, we need not be concerned that the former was introduced into the latter. He argues for extending the Pri Chadash’s interpretation of ein b’edro tamei to allow chalav akum even where non-kosher animals are milked as long as a large price difference discourages mixing the milks. The basis for this approach is the Gemara’s assertion (Avodah Zarah 34b) that although the Mishnah (Avodah Zarah 2:4) prohibits non-Jews’ muryas (oil from pickled fish, which sometimes contained wine) due to concern that non-kosher wine was added, the prohibition does not apply when wine is far more expensive than pure muryas.