Israels Iron Dome was designed to use cheap interceptors - we are talking $100K each, not millions. The downside is range, its more of a point defense system. But its rather compact and should probably be quite easy to “navalize”.
Its surprising the Israelis havent sold more.
As to the rest of your comment, the one system in common across some of the recent wars and threats is Patriot PAC-3. Israel has PAC-2, intended mainly for antimissile use, but its being replaced by the Israeli Davids Sling. The Red Sea troubles have used Naval systems, not used in Ukraine or by Israel. Other interceptions in the Israel attack have been by US, Jordanian and Saudi (and probsbly Israeli) manned aircraft using AAMs.
So its quite a diverse lot of missiles, not stressing any one “pool” of ammo, yet.
The other downside of Iron Dome it its not designed to intercept high speed missiles.
Thanks for the detailed answer.