I don't understand the cost issue. Cabela's has tungsten beads for $5.75/20. They are not slotted but they do have a bevel. So for 30 cents I can have a small head that sinks fast. When I drive out to New Mexico or Wyoming from Florida, the cost of the fly is not a consideration. On small nymphs I thing the smaller bead is better than the larger brass bead. I also prefer black beads instead of brass colored beads. I have been looking but still have not seen a nymph with a brass colored head.