Red Dot is like the Reject Shop … quite different from the $2 shop … I have also tried in those shops myself, but saw nothing. Red Dot sell some ok stuff but a lot of it is C R A P! 
I have also seen them in Bunnings but they are soooooooo expensive … I believe Lisa bought her’s from Bunnings too, but if your bun is somewhat of a cage biter and cage arranger the ties can get chewed through and cubes can get damaged by the pulling around. I saw Lisa’s set up and a lot of her cubes had been damaged by some of her buns’ biting, subsequently causing the plastic coating to fall away. However, Lisa has 7 bunnies 
Another option would be a storage shop … something like Howards Storage which basically storage items … but once again they are expensive.
Have you tried using a pen … they do take up much more room so if space is a at a premium for you the cubes are the better option. One bun would probably not do so much damage. Pens are a good idea as you can move them around to please yourself. I also set my pens up outside when the sun is out and put the buns and piggies out there in the fresh air … I think they need some fresh air, just like us humans
and that way they can graze on the grass.