Where to find wire for a small animal cage?

I am wanting to build a chinchilla cage because store bought ones are too expensive and most are made with plastic which is toxic. I have no problem building the inside of a cage, like shelving and things. My problem is how to build the frame/cage part. I can't find any wire suitable for a full size three level cage. Does anyone have any ideas? I've heard off people using organizing cubes but the issue with that is it doesn't seem that stable for a tall cage with wood shelving. If anyone knows where to find a real cheap wire cage that only has 1" openings please let me know(I thought about using a dog crate but the openings in the wire is too far apart a chin could squeeze straight out). Or if anyone knows where I could find wire that is durable enough for a chin (Tried chicken wire and its too flimsy) that I could form a cage with. Any tips would be great.