All sold by one seller, whose listed address appears to be a residential building in a rural area south of Frankfurt. I'd probably keep my money in my pocket....
But Amazon Marketplace is exactly the same as eBay, anyone can sell, there's no vetting of a seller, so there's a lot of fake goods and dodgy sellers. And it's incredibly easy to fake 5* reviews, you literally pay a company and they'll flood your market page with hundreds of 5* reviews.
Always make sure you buy from Amazon direct or a reputable seller who hasn't just popped up.