if you are planning on building a new cage once they get bigger i wouldnt spend much on their current one... bcos they wouldnt be in it for long... if you can, make the cage ya self rather than buy one. hell of alot cheaper and you can make it to what ever size and layout you want... have a look at some of the other peoples picks of their cages on this site they can give ya tips on how to build one... or me hehe
nev