3dscapture.com

Oh yikes! Sorry I gave you a bad tip.

Since you live in Europe, this could suit you better than it would for me since the 3DS is region locked; here's an ebay listing for someone selling (what appears to be) a Loopy card in Italy: https://ebay.us/uwljlw

You don't really need to worry about being able to sell it on ebay. There are people out there scoping out the site daily for new listings (doesn't matter if it's Katsu or Loopy); they tend to get bought the day they're posted if it's not an auction.

That said, if you're interested in selling it, I ...