A house-rule I saw mentionned in one of such discussions, and that I like very much, is that the reason Adamantine is so strong is because it is unalterable.
Adamantine ore can be melted, refined, and forged into something. But as soon as it cools off, it will not budge anymore. In other words, a massive adamantine door can be used only to be placed in a massive doorway (with robust hinges, because it's heavy). You can't melt it and use it for something else. There are no such thing as adamantine scraps.
You'll notice that the cost of adamantine items doesn't vary that much according to the weight (just look at the blanket cost of adamantine weapons). They vary according to the work a smith has to do in order to build it.
With that rule in mind, I'd say adamantine ore is in fact rather cheap and refined adamantine is worthless. You have bits of adamantine wires extracted from a warforged's carcass. Good for you. If you manage to find a use for them, you'll be lucky! But otherwise, they're pretty much nothing more than curios.
At least, honest-to-goodness biological bones can be easily sculpted into crude tools or weapons or flutes or snowgoggles or something.
Of course, this doesn't solve the problem of mithril-laced warforged bodies.