What does that thing do anyway, allow you to write with a pen?
It's basically like being able to draw on your computer screen without actually drawing on your computer screen. Because that would be silly. Unless you had a tablet PC, but those are hella-expensive.
I have a regular Bamboo myself, got it for $79.99, which is about £47. I know it's over your limit, but it's a good one. Of course, if you don't need any of the shortcut buttons (a zoom wheel, scroller, and 4 customizable buttons) then go ahead and get this one. No sense in buying something more expensive if you're not going to use the things that make it more expensive.