WHY DO PUBLISHERS TAKE THE BRITISH BOOK BUYING PUBLIC FOR MUGS?

Once again, this March there will be a volume off G R R Martin's A Song of Ice and Fire (ASIF) published in the UK and due to the size of the hardback edition it will be sold in two parts. This obviously means paying out for two paperbacks and I am not impressed. I know some booksellers will do deals of some kind but that is not the point.
The same thing happened before with book 3 in the series and with the first volume of Brandon Sanderson's quite marvelous (in my opinion) Stormlight Archive - The Way Of Kings. My gripe is that on visiting Sheffield Space Centre (and if you haven't visited there you really should) I have found 1 volume editions of ASIF 3 and The Way of Kings printed and published in America which were of good quality (both paper and cover) and, more importently, of about the same price as a uk paperback.
So my question is, if the US publishers can do it, why can't the UK publishers.


On a seperate note - Being Human started back again on BBC3 last night (Sunday Feb 5th) and it was marvelous. Looks like the series is going to keep on getting stronger even without 3 of the main cast. Good Times.