It is cheap, it's alot cheaper to buy a Projump hoof bracket than it is for a Powerskip one.
The cheapest option is to make tyre socks with bicycle tyres. Or the next cheapest would be Jason's "Hoofies", they last forever. I used to get a full week of bocking (about 14 hours) on a pair of tyre socks. Jason's hoofies, have lasted about 30 hours already and still show hardly any wear.
I hope this helps.