After a quick Google search I found on Reddit that this is a legit site. The game is the European version, but since the Switch is Region Free and this game has no DLC I went for it. For what I read, the free shipping does not give you a tracking code and it takes about 2 weeks to arrive. I payed with PayPal.
Edit: I just saw that they also have Pokemon Mystery Dungeon Rescue Team DX for $40.99