[Avodah] How much for the mayo?

[Elazar M. Teitz]

I wrote, "Then there is a din against profiteering in d'varim sheyeish
bahem chayei nefesh." That is, in such matters the din assesses a
"maximum allowed profit, which is a one-sixth markup." As the g'mara
states in Bava Basra 90a, "hamistakeir al yistakeir yoseir mish'tus." To
the best of my knowledge, this means one-sixth mil'bar, what the seller
paid for it, and not one-sixth mil'gav, what the buyer buys it for."

It was pointed out to me off-list that the Rav Shulchan Auch writes that
the one-sixth is indeed mil'bar. However, I interchanged the meanings of
the terms. Mil'bar (literally, from outside) means that the additional
amount, when added from the outside, becomes one-sixth of the total --
what we would call one-fifth. Thus, for an item which cost $30, the
seller may charge $36, so that his $6 profit is one-sixth of the sale
price. Mil'gav (lit., frpm inside, and is probably properly pronounced
"mil'go) means that the additional amount is one-sixth of what is already
there, or $5, so the sale price would only be permitted to go as high
as $35.

EMT