A few years ago I made my first Contraforte reed case out of tupperware, that case is a little beat up now so I made a new one. This is made from an acrylic box from The Container Store, some thick foam and duco cement. I drilled holes on both sides for air circulation, but I mostly keep my reed cases open when at home.
This case is for Contraforte reeds, but now I’m thinking about making a bassoon reed case. All together this was almost $15 which is still cheaper than the commercially available options.