Looks like postage to the US will be about $20 for a parcel of between 0.5 and 0.75kg. Since a doorstop is a pretty robust thing, packing can be limited to a tough postage satchel with some bubble wrap to hold the stuff together. Dunno how much one of these things weigh, probably a lot less than 50g, so we can accomodate at least 10 in there, perhaps up to 20, so that makes perhaps $2 or less amortized international postage. Not bad.