I've seen packs at my local target on two occasions, but that was nearly 6 months ago now... I'm just going to try and get villager trades done here. I'm just lucky that my new file had Merengue as a starter villager.
I got a full box that completed the set when the Welcome Amiibo Cards got released. It had a full set with 10 repeat cards.
The store ordered them for me. That's the only place that had them but they stopped selling them.
A lot of stores went to online only because the cards weren't selling during the summer of 2016 and people were stealing them. The cards and figures were taking up a lot of shelf space when few customers were buying them last summer.
Nintendo should have released the update earlier when they knew customers had slowed down on buying them for the Happy Home Designer game. That's a lot of money to pay for Series 1 to 4.
Since the stores are tired of carrying them I wish Nintendo could sell them thru the Eshop as a code. Yes you wouldn't get the card for the collection but you would be able to use them to invite a villager to your town or buy items.