>>The big difference is that the breathable bags can be completely filled (which costs more to ship) and the other bags require an air pocket at the top<< I received some killies in Kordon's bags last fall. The shipper used the same amount of water he would have with normal bags. The difference was there was no pocket of air in the top. I see two advantages. One, a smaller shipping container can be used because the bags take up less space. The shipping cost would be the same as the weight would be the same. Larger shipments may be less because you could fit more fish per box resulting in fewer boxes. Two, added protection against errant shipments. The breathable bags would provide better protection for fish in shipments that get delayed. Yes, I've heard stories of fish surviving weeks of misplaced boxes with normal bags. But I would venture a guess that fish in the breathable bags may be in better shape following such an ordeal. The big question is, "Are these differences significant enough to warrant the additional price?" For most hobbyist that ship occasionally or just bag fish for local shows, probably not. If you ship often or far, then maybe. Ideally, the cost should come down over time, especially if commercial shippers start to adopt the technology. Then the incremental difference would not be so hard for the hobbyist to swallow. Bill Vannerson http://ourworld.compuserve.com/homepages/william_vannerson