Some of the stores in America aren't even putting them out though. My mom went to best buy to try and find some, one young employee checked the back for her and told her they were completely sold out, but sounded odd so she asked a second employee and he went and pulled out a whole box, saying they have tons but they just aren't keeping them out for people to see.
It really just depends on where you go, but most online shops let you check the stock in store so you can always do that before going! :l
My bf recently got me the game as an early bday present and we went amiibo card hunting all around our city as far as we could and everywhere we went, they were sold out. He's pretty determined about getting me the cards so he asked every employee if they had more in back stock but in every Walmart, Best Buy, GS, and Toys R Us, all said no. So hopefully this isn't the case that they're not really checking cause going around everywhere is exhausting!
In the end, I settled for ordering them online. I do hope the stores restock because it is more expensive to order than to walk in and purchase them physically.