The Chinese ones are actually soooooo cheap, no kidding. I really like the edition, it provides you with a lot of information, like all of the known ossias and the performance commentaries.
The ones in English are rather dear, but quite worth it, I suppose. But why not get the Chinese, which also has English!
I have the Etudes, Ballades and Concerti, but I would have bought the whole set in Beijing had I had more space in my luggage!