If rumors from NeoGAF are true, this wave was just manufacturing in january. The other ones were up to 2 months in production, so yeah, the rarest amiibo is probably one of this wave. Most likely Ness, if you ask me.
I guess I'm not the only one with that theory. I will bet that many reseller was waiting for this moment and bought huge stocks from amazon. Finding the not common amiibos is really not easy in germany. Rosalina, King Dede or Shulk for example are out of stock everywhere since weeks.
Edit:
I build my own amazon link with all preorders in the next 12 months for all consoles. I'm checking it regularly so I never missed any items I want. The good thing is, that items show up there a couple of hours before you actually can preorder them. Like the amiibos today. Saw them first this afternoon. They went live @ ~6:50pm.
For Germany/UK/US/FR
http://www.amazon.de/s/node=300992&f...sedate=1y-365y
http://www.amazon.co.uk/s/node=30070...sedate=1y-365y
http://www.amazon.com/s/ref=sr_st_po...opularity-rank
http://www.amazon.fr/s/node=530490&f...sedate=1y-365y
Works perfectly.