Gordon is quite right; I had always though these were called Morning Stars, but I was wrong. A morning star was a wickedly spiked mace.
http://en.wikipedia.org/wiki/Flail_%28weapon%29If you have to order 5x handle, 5x chain and 5x ball, the DS price would rapidly add up to close to this eBay price, but every time I've had one of these in a set, the 3 component parts have been together in a sealed mini-bag, so I suspect if you order, say one handle, you'd get all 3 parts anyway. Let us know what happens Mike.
As a weapon the Flail has always seemed particularly vicious, but awkward and requiring much skill and practise to wield without danger to the user or his fellows. In skilled hands though, it might be used to pull a sword or shield out of someone's hand.