You'll find the retail price of CNC knuckles anywhere from £25 - £40. Have a chat with Lewis at Access and see what he can do for you, he's pretty helpful.
They are not Futaba servos and are copies of the Tower Pro ones. There has been loads of chat on other forums about these and are reported to be very hit and miss on the quality. You get what you pay for with servo's, but found the genuine Tower Pro ones at £12 each to be fine in a Hyper 7.
The ones listed above on are really cheap, and if they work ok for a few months then nothings lost.