I always wear a helmet when riding, even just for the smallest trips, and for longer trips it is often a full-face helmet. So, knowing the value of a good helmet, I want mine to be in tip-top condition. After all, any helmet that has been dented or scratched deep enough to penetrate the protective outer layer can't do as good a job protecting you as an undamaged one.
Harley-Davidson's helmet bag is simple enough – a water-resistant nylon outer shell, soft, nonabrasive woolly interior. The helmet bag has one long zipper that makes it easy to put the helmet in and take out, as well as heavy-duty loop straps. There's also a tuff-and-hook flap, complete with Harley-Davidson Bar & Shield logo, to store a cloth for wiping down the visor. The Harley-Davidson helmet bag is small enough to roll up into a space a bit bigger than a Coca-cola bottle, but big enough to easily hold and protect a full-face helmet. And it's a good size to stow into an overhead storage compartment in most airlines.
After all, working in the motorcycle industry takes me abroad often. Sometimes we fly there and rent a local motorcycle or do some testing. And I wouldn't feel right wearing a chewed-up helmet, and you shouldn't either. The Harley-Davidson helmet bag was a gift so I cannot say exactly what it costs, but it cannot be that much.