Tried switching countries around. For their "free" shipping, if I switch countries from mine to the US the cost of the book drops to a third of what I was originally seeing. Goes from quite expensive to fairly cheap.

When shipping internationally, you need to declare the cost of goods shipped for customs purposes - but do you need to include in that the cost of the shipping? If not - I suspect not but am not 100% sure - this approach of building shipping costs into book price may result in a massive increases in costs paid to import the books in question.