Question

In honor of the Rabbi, hello,
The Mishnah at the beginning of tractate Kiddushin brings a dispute between Beit Hillel and Beit Shammai about how much money is used for betrothal: according to Beit Hillel, a perutah, and according to Beit Shammai, a dinar.
The Avnei Nezer investigated [siman 27, se’if katan 1] whether, when we say “money” in the Mishnah, the intention is specifically a perutah/dinar, and that this is the measure forever—in which case we follow Maimonides, that a perutah is half a barley-grain of silver and that is always the measure—or perhaps we follow the current coinage, and in every era its “perutah” means the lowest-value coin.
And the above-mentioned Avnei Nezer explained that the view of the Ritva is that we follow the current coinage.
And this is his wording [the Ritva]: “Strictly speaking, Beit Hillel should not have taught ‘with a perutah,’ for
          in the verse it says ‘money,’ and Beit Hillel hold that this does not mean actual silver money,
          but rather monetary value, namely the value of a perutah. And since that is so, the perutah itself, which is
          made of copper, is merely worth a perutah and is not silver money. Rather, since
          Beit Shammai taught ‘with a dinar,’ for otherwise that would not suffice, and since it taught ‘with money,’
          the tanna also taught, according to Beit Hillel, ‘with a perutah’ and ‘with the value of a perutah.’ But there, in the chapter HaZahav, where it teaches
          ‘there are five perutot,’ it teaches only: ‘A woman becomes betrothed with the value of a perutah.’”
Seemingly, from the Ritva’s words there is a sharp distinction: either monetary value or silver money, and he decided that it is monetary value.
However, the Chazon Ish, Even HaEzer siman 148, explained the Ritva to mean that when he wrote “monetary value, not silver money,” he meant not silver as a metal in the plain sense, but rather coined monetary value equal to half a barley-grain of silver. And that is puzzling, because nothing in the Ritva’s words seems to indicate anything about a coin or half a barley-grain.
This time I tried to keep it short.