The Critter Trail isn't a complete waste though as it can still be a carrier!Of course,it is an extremely expensive carrier at that
It might be possible to find a half square meter(775 square inches)rabbit cage and then just mesh the bars,but there are certain bins available that could make a good cage.Another option would be Ikea hacks like a Detolf or doing two Billy units,but as long as the end result is a single floor area around 775 square inches total it will be fine.DIY can be a bit expensive when you're only making small cages,so Ikea hacks could work out better in cost.