price of brass vs steel? cast? pipe fittings = weird

Actually "they have" LOL. Now that we have all the offshore manufacturers, it is sometimes difficult to get various brass fittings---in U.S. / SAE types--that have U.S. wrench hex flats on them. And some of them are NEITHER U.S. or metric. They are just "off"

The smaller fittings made from hex bar stock are standard SAE sizes. The larger fittings that are made from castings are oddball sizes.