Once fired brass sells like hotcakes, gun hobbyists often buy these to reload their own ammo. Ammunition is NOT CHEAP, especially if you shoot often, and lots of people do, there's a big market for this. The scrap yard will give you the lowest possible value for any item, if you have something that has value to a consistent and large market, the scrap yard should always be your last call (unless you're more satisfied with the quick sale, of coarse).