When we fly with our sabers for conventions, we use a poster tube, meant for art and blueprints and such. Seems to be quite a bit cheaper. We used some spare EVA foam at top and bottom, and it fits my 32" blade and partner's 38" together.

https://www.amazon.com/Poster-Tube-Strap-Blueprints-Expandable/dp/B01DLYJJWG