I know this is a kind of European product as I have never seen them on any non-european website. Here in Holland they cost approximately 70 Euro, some 85 Dollars.
It's a dutch webshop available in english. you can find the polybutler by searching on it. They also export as far as I know.
It's an awfull lot of money, but I use mine now for some 10 years without cracking/ defect or whatsoever. It's worth the money if you're into rc-racing! Perhaps you can ask your local shop to import one or find out where those come from.
YOU CANNOT RACE WITHOUT IT!