The dream about the cage is interpreted as the symbol of the trap. Perhaps you feel the lack of space, you need your privacy and independency, but your relationships, job or friends doesnt let you be who you wish to be. The bird in the cage could indicate the happy marriage. If you buy the cage in a dream, then it means some stability is coming in your life.
Cage dream meaning
Read more about dreaming of Cage in other dream meanings interpretations.