Assuming these single packs are priced the same as the Mario pack, it's 19,980 Yen for the 30-block set vs. 11,920 Yen (2,980 each) for all four 3-block sets. You're only getting 12 blocks, but if you only want the amiibo, this might be the way to go. Obviously, we don't know what, if anything, is getting US releases yet...