This may be a bit late but good news! Better World Books is now offering free shipping worldwide, just like what Book Depository offers!
Before this, Better World charged a shipping fee of USD3.97 per book. They had all these bargain promotions where you can buy a number of books at USD15 but then since I come under the 'outside US' category, there's the USD3.97 per book to think of.
I loved Better World before this because they had a great selection of old and new books (I bet they still do now) at affordable prices. I'm looking forward to shop for books there again.