I have one I use for my machines. Love it! And yes, sometimes it can seem a little "glarey" after a couple of hours. I just move it slightly to the side so the light is not so direct when it bugs me. Because even with a year old machine, the "new, brighter" LED light on it is useless! I can't tell if its on or not in the daytime. Also have trouble seeing the little "computer" window! If the bendable is on, the back wash of light is enough to make that visible, too. So even tho I think they're very expensive they really work for me! There are double sided sticky things that I think would work to attach the holder to another machine. I found I'd like more of the cord "hangers" though.
I don't know what makes them so expensive, but I'm sure glad I have one!