iron and leather are both pretty plentiful. Blacksmith Vendors sell a pretty good quantity of leather and iron. If you make daggers, you're using one iron ore and one leather strip (1/4 of a leather) for each item. if you make leather bracers, you're using one leather and two leather strips (1/2 leather) for each item. if you have large amounts of both that usually means you make make far more daggers than you could leather bracers.
Well, yeah. But it keeps it challenging =P And if you prefer making daggers, there's always to option of going out and mining it yourself (saving money, YES) =D I personnally prefer the hunt over mining since it lets me get better sneak and archery too.