Why Not? I think it would be very useful.
I never bothered learning Gate Construction yet I know there's a few guilds out there that that's all they do. Besides I got a Sprite to feed.
I trade all my Moonstone, Crimsonite, Valestone, Luminite to Gate Construct Junkies in exchange for Dark Matter. It's a Win-Win! They get what they need without guys like me randomly pumping minerals in Arcade for a small crown payout (and ruining what they were doing) and I get what I need.
I support this. I have always wanted to trade minerals, now I have just another reason why to. And dat ish bcuz of spwites :3
~Z