Animal Crossing Custom NFC Amiibo Card on Ebay?

Everyone who currently plays Animal Crossing New Horizons probably knows that ridiculously high prices are sometimes charged for the Amiibo cards.

So on eBay so-called "Animal Crossing Custom NFC Amiibo Cards" are offered, which are much cheaper. But not from Nintendo.

What is it exactly? How does it work and has any of you ever used something like that? Is it worth buying?

These NFC cards were bought as "empty" cards and then the resident code was loaded onto them. So these cards are made illegally. There are still disputes as to whether they can be made, but they should not actually be resold.

Hope I could help you. C

I have something and they work just like the original ones. However, I got empty chips and cards and loaded the code of my desired amiibo on it myself.

It makes more sense because they are cheaper. I know a lot of people who do that. The console sees it as original because the code was copied from the original (so to speak).

Ok, so if you use them there are no negative consequences? Nintendo doesn't ban you or anything?

(Sorry for asking so stupidly. But I've already invested almost 250 hours in my island, so I don't want to take any chances.)