I agree they are pretty much a standard price.
We couldn't even get hold of one after my accident so had to go for the Gatehouse one instead - well worth it though it's fantastic!
I saw some in Decathlon - seemed a bit cheaper than in tack shop. They also had a smart cheaper version which was EN1384 standard and about £45 - nearly bought one even though i didnt need it !!
I have been searching the net,and the cheapest i have found seems to be from Safety plus equine.It was around the 72 pounds with the postage.
I have ordered one,so hopefully the company will be ok.Has anyone any experience with them?