Bug is inside for all the day, I have 2 dogs and I don't trust them alone, even though they do get along when there is a glass between them.
Yes, the storage cubes are pretty expensive and to be honest if your happy with a pet enclosure you find then I would settle for that, over seas the cube wires storage is more readily available so its less expensive than over there.
Its not enough to just build the wire enclosure, you also need to create a floor for it, so i'm going to bunnings to get some wood and custom build the floor and have a latch for the doors. It will probably end up being the same as a good quality ready made enclosure but the difference is mine is custom to what I want.