Argos have a medium sized pet cage half-price in their sale. Seems to fold flat for storage. Not sure if it is cheap or any good even, but thought it might be useful for some people:
http://www.argos.co.uk/static/Product/partNumber/8706014/Trail/searchtext>PET+CAGE.htm
It's instore only, but I did check a few postcodes and they are in stock in some branches. You can reserve and collect.
http://www.argos.co.uk/static/Product/partNumber/8706014/Trail/searchtext>PET+CAGE.htm
It's instore only, but I did check a few postcodes and they are in stock in some branches. You can reserve and collect.