when I bought my kit it had the white part that the cables wind round, cables and clips in the box. It was about £36
If you get the same kit they are easy enough to do, the lobes that the cable runs round have eccentric parts on there that allow you fit the cable without needing much tension. As soon as you test it the cables pop onto the runners.
The part you've put up does seem like a bargain with discount though, just remember you'll have to drill out the speaker and rivet it back on