i found some at jb-hifi many months ago, but that is in just Australia and New Zealand. Amiibo cards are region locked i guess. so my amiibo cards would be in the EUR region
They're not region locked (thankfully). The only difference is in design (EU cards have the EU date format, for instance)
I get all of mine from Amazon or the Nintendo official store (they're the cheapest on there!). I only recently started collecting them so I don't think you're too late to start at all ^_^