I bought a set of those off eBay myself thinking that I might put them on, but I've decided to keep my 5-spokes. But they're the silver ones, not the anthracite ones. I paid £120 plus £20 postage, and am only hoping to get my money back, as opposed to making a profit.
The wheels didn't originally come with centre caps, and I also have those, which cost me approx £50.