The biggest weight is the packaging. That weight accounts only for the box. With bubble wraps and all, it weighs a little over .8 kg, but I guess they aren't going to add that to the total packaging weight..
Either way each set w/ packaging will weigh a little over 2 kg, so you'd have to look at the 2.5 kg shipping rate.
If you want to make your own ALPs plate, I have the file for it. Let me know if you want it.