Technically I'm not a Kiwi. I'm an expat American.
All the books I had issues with re: binding were ones I'd ordered from overseas. The ones I've bought locally haven't had any issues with the binding coming apart. (Instead, some of them have reeked of the glue used in the binding.)
I used to order all my 5e books from the Book Depository in order to get the free shipping but lately I've just been popping down to my FLGS and purchasing / preordering them there, as it's quite convenient now that I work in the city. It does mean I usually have to wait longer but that's OK. I want to support them.
That said, I did just order a copy of the Curse of Strahd Revamped and the accompanying mini sets from Amazon. They arrived super fast!