I'm patient, and all this will do is to make me order a little more rarely.
In my experience, if I order two items, they generally arrive in two boxes. So I don't think this will save them much in shipping costs. Perhaps they are hoping people buy more to meet the minimum.
Paper book shipping is still free worldwide, with no minimum, from their
www.BookDepository.com subsidiary. Prices are several US dollars over that on the US Amazon web site, but it's a great bargain for international gift-giving.