Thing is, beyond the commons, they don't sell that much over here. I bought Ike and Sheik from my local Smyths, and they had three of each when I went there, meaning they had two left after my purchase. They still have them in stock. Low stock, of course, but they are there. Probably the exact same two. I bought mine two weeks ago. If this was the US, those would have been gone day one.
I'm sure more people over here would buy these if they were cheaper (Marth, WFT, and Villager sold out likely because it was around Christmas time and people had vouchers to blow), but as it is now, it's only gonna be people like me who just happen to be the odd one out in Ireland.
What I hate, is that Irish retailers list Little Mac and Rosalina, yet never get her. And now I am gonna be worried about one figure just not making it over here every wave, and it's annoying.
It was also especially confusing in Rosalina's case - people in Ireland DO know who she is. Certainly more than say, Sheik or Ike. Heck, the majority of Irish players I randomly see in MK8 online play as Rosalina (I can only recall two times were they weren't, and 5 times were they did play as her). My cousins, back in the MKWii days, specifically had me loan them my copy of Super Mario Galaxy JUST so they could unlock Rosalina easier. And the big 3D Mario games sell here, so people have played Galaxy. I was so shocked and upset to find out she wasn't being properly sold here.
At least with Little Mac I understood why (even though I still disagree). But with Rosalina, there was no excuse.
The rarity of characters might be based on this question:
"How likely are you to play as this character in an upcoming game (that is not a party/crossover game)?"
Can't say I agree with this philosophy at all, since most of the cult favorites tend to be characters that aren't big stars. By definition, if you're a "big star," you can't really be a "cult favorite." Mario, Link, Donkey Kong, Pikachu... these are big stars, and super common. It makes sense. And yet, Rosalina has a strong fan following in the West and still managed to be fairly rare. But are you likely to play as Rosalina in a game? Well, as you said, MK8 features Rosalina! Mario Party 10 will, as well. I dunno.
I suppose the philosophy behind the question, if I'm right, would be to use Amiibo to sell games that otherwise wouldn't be huge sellers. However, if that were true, you'd think Shulk wouldn't be one of the rarest Amiibo of all!
My theory just cannot comport with how Lucario turned out, though. Lucario is a popular Pokémon, especially with the younger players. Lucario is probably even more popular in Japan than he is anywhere else. No, he isn't used much in Smash Bros., but as far as Pokémon go, he's up there. How that translated into a rare Amiibo, I will never know. Budget? Must have been budget. There was only so much money to spend on producing figures in wave 3, and Lucario was low seed, so to speak. Still, wave 3 could have easily supported one more common/uncommon figure. Wave 3 was mostly rares! That's what you get when you launch such a huge number of figures all at once, I guess...
Well, if "how likely is this character to be playable" isn't the criterion, the only other criterion that makes sense is:
How much brand recognition does this character have?
Nintendo probably did a few focus groups. They'd put up character art of the Smash cast, and quiz people on who the characters were. More successful answers, more common Amiibo. I could see this happening. Reminds me of this video... lemme see if I can find it...