Unless you intercalate in law and ethics, you really won't need to buy a book in it for med school. You'll be able to borrow what you need from the library. That's what I intercalated in, and I still only bought 2 books, both during my intercalated year, and wouldn't have bothered otherwise.
The book we used at Birmingham mainly was Principles of Biomedical Ethics by Beauchamp and Childress. (I think this may be in your link above but am on dial up internet in Africa so haven't tried it) But there were loads of library copies and so I never bought it. I can't remember the name of the one I actually ended up buying that I used a lot. But I really would think twice about spending lots of money like that at the moment, even if it's something that interests you.