It's a fair point. But they could have done so if they just removed the rep gains. I mean, it'd make no sense trading mats for just marks if your rep isn't high enough. 30 vangard marks for 60 mats 50 mats for 5 crucible marks/vangard marks and exp (no rep) So basically you'd be trading 30 vangard marks or crucible marks for 5 marks of the opposite faction with no gain to reputation. This would assure the only people trading in mats for marks are those who need the extra couple marks for gear from a faction they have already leveled.