I've got a Roccat keyboard and mouse and I don't notice any difference between this and a £20 set. Any old mouse from Amazon with gaming in the tag will do me
I've been looking for a decent wireless mouse for a while, spent $30-$75 on mice, but I've returned to my cheap wireless mouse that out performs the others in my opinion:
I've been using the Logitech G402 for a while, and its definitely one of the better ones I have used. It's light weight, not as clunky as other gaming mice, and suits all my needs for a mouse.
Just bought the logitech MX Master mouse. It's pretty sweet. Feels really comfortable and I don't notice as much wrist pain when I use it compared to other mice.