I was provided an NHS walking boot after breaking my ankle. It didn't provide any support and was more like a ball and chain. This aircast on the otherhand fits snuggly and provides great support. I walk all over the place without needing crutches. I often forget I'm wearing it.
I got the aircast new for a total bargain on ebay, but I wouldn't hesitate to pay full price if necessary. Its worth it.