Yeah, I don't know if a group buy on shipping actually works. You'd have to be extremely strategic about it. Not worth the effort, IMO.
The stuff I've bought from Surugaya via Rakuten was so f*cking cheap I was glad to pay the shipping. I've made two orders with them. One went perfectly, the other wasn't as perfect.
Basically, I ordered some stuff, the biggest thing in the lot was the Gundam Master Grade Movie LD box. They sent me an email saying, "The item is missing the certificate". I looked up some pictures of what came with this box and decided that I didn't need no stupid certificate. When I got the box of stuff it was...a lot thinner that It should have been. The other items (Galaxy Express 999 Galaxy Box and Royal Space Force Memorial Box) were perfect but the Gundam box...? They sent me...disc 8. Yeah, just disc 8. No photo CD, no outer box, not book, no discs 1-7.
OK, now if you look at what I payed for this thing, about $10, you'd say, "Dude, are you stupid? A $300 LD box for $10, of course somethings up and its worthless!" but its not that easy! I just bought the entire Mobile Suit Gundam TV series, both box sets, which was way more expensive, for like...I don't know, $35 or something, so for the most part you do get INSANE deals from this place. The problem is that the photos are stock (and puny) the descriptions are non-existent and you really don't know exactly WTF you are going to get.
For the record, if you were to only have one LD from the Master Grade box, LD8 actually is the best one to have.
It contains one side of old trailers, GunPla TV ads, and the footage they made for the Saturn game in (obviously) much higher quality. I'm...a little pissed though, and now I'm really skeptical about anything else I get from them. I have every intention of spending a lot more there in the future though.