Amiibo are a luxury now. They are awesome and cheap... if you can buy them for retail. If you have them all, you are a God among your like-minded peers. The hunt for them make them valuable, the rarity make them valuable, and the announcement of more and more functions for them just keep adding in that value.
And the fact that the rares don´t lose that value means people are going to keep trying to get them. They buy it at $14 because they think they can sell it at $20 They import it at $20 because they think they can just sell it at $30.
We can blame Nintendo all we want, but this whole clusterfuck is making people talk about Nintendo again. Normal, casual, regular people who have not even bought a Wii U yet but do remember their nostalgia for the characters. There is no such thing as bad publicity.