Consider the material the cage is made from. An antique wooden cage may be pretty, but think about this: most birds are either bored or powerful enough to bite away the wooden rails and escape, and porous materials such as wood can hold dormant viruses much longer than less porous metals. Also, do not buy a dirty cage. Unless the cage has been thoroughly cleaned and disinfected (and it is obvious just by looking at it), do not buy it. If the cage is missing its waste tray, has broken or dented doors or the cage top does not meet properly with the sides and base of the tray, do not buy it. If you are buying a smaller cage, know what will go in it. Finches and parakeets may live happily in a small cage, but cockatiels and parrots need as much space as you can afford.

On the Other: Cost-Effective and Ecofriendly

If you are getting the cage from a friend or relative, you may know very well how clean they kept their cage while their bird was in it. If it is a clean metal cage with no burrs, dents which prevent the doors from opening, has a cleanable slide-out waste tray, and if it is the appropriate size for your bird, why not? Buying a used cage is far less expensive than buying new at a pet store, and you are recycling. Make sure they have cleaned the cage thoroughly, so there is no dust or feces on any of the bars, toys, or tray, and that they have used disinfectant.

Bottom Line

A used cage can be safe and cost-efficient if the cage you get is metal, comes with all the things a new one does (food and water doors work, the main door works, and it has a slide-out feces tray), it's appropriate size for your bird and it is thoroughly cleaned and disinfected.

Source:

"Cockatiels for Dummies"; Diane Grindol;2001