So, if you go look at Amazon.co.uk and search for 'Childred of Hurin', you will get three hardcover matches.

(Not sure if this link will work, but... try it here)

One has ISBN 0007252234 and is £0.80 each (?!) (This is the ISBN for the deluxe edition)

One has ISBN 0007246226 and is £18.04 each

One has ISBN 0007252250 and is £0.20 each (!!?) with a pub date of September

Last one has ISBN 0618894640 (This is the Houghton Mifflin edition marked for import to UK) for £12.59 each.