Is paying the monetary equivalent of the expiation permissible?

Primary text

There are two views on the permissibility of paying the monetary equivalent (value) instead of the specified half Dinar of gold. The soundest opinion is that it is permissible because it is a right where either of the two standard currencies (Dirham or Dinar) suffices, as is the case in other financial obligations. This is supported by the general principle that if an equivalent amount of wealth is the goal, any form of that wealth suffices, like Khiraj and Jizyah.