Quote Originally Posted by DiBastet View Post
How? Think with me:

If, only if, the dust is the equivalent of the "half price in raw materials", and I believe it's simples to assume that this dust is a very raw material, since you can use it in the place of the generic "raw material"...

...then why in Mephisto's name can't you sell the goddamn dust for what it's worth? It's like gems, magical gems and money! Why?
It's not like gems and money: Gems and money are a medium of exchange, "bought" by people who want to then use them to buy other stuff with. Dust is a somewhat specialized product, more akin to spell components.

If the OP does want to make dust into a trade good (his choice as the DM), then dusting would have to provide only a tiny bit less than 50% (if it's exactly 50%, then all adventurers will dust rather than going to the effort to find a buyer at 50%; if it's substantially less then nobody will dust, preferring to sell it and buy dust); it'd be a very difficult balance.

It's like buying 500 gp of ruby dust for 450 gp and not being able to use it as material component because you bought for only 450!.
No, it's like finding 500 gp of ruby dust and not being able to sell it for more than 250 because while rubies are a trade good ruby dust is not.