there is some on ebay in that size for £50 a tyre.
i have a set of snow chains that are fucking awesome in the snow and going to get a spare set of steelies to fit them to as fitting them in the snow was a pain in the ass, so will just have the wheels in the boot if it snows.
also been looking at snow socks as they are easier to fit, but you cant drive on tarmac as it will wreck them pretty quick