You all forget that gold does not have the same value as in are world for a very good reason. It's called Transmute Mineral Ore, a spell that any moderatly knowlegable mage can perform that turns iron ore to silver and silver ore to gold. So gold just likly isn't as rare in Tamriel as it is here on Earth. Is it as comon as iron? No, and that is why it's worth more, but Ebony is something that can't be transmuted as far as we know and that is why even though it isn't a precious metal it is still valued more per unit.
