I'd never buy from anyone who isn't an authorised dealer with a shop or established legitimate website and trading address. Amazon is a conduit for private sales, like ebay, and you GET WHAT YOU PAY FOR... Too good to be true? It is! It isn't Amazon, it is a private sale.
Last year I bought some Audio Technica cans from ebay after links in another forum. They looked ABSOLUTELY real, had over 100 positive feedbacks, and were selling like hotcakes. They sounded as cheap as stock ipod buds.
I sent them to AT UK and they wrote back saying they were as fake as Jordan's top shelf (well, the image itself should make you remember to beware!).
By sight, you wouldn't know.
Fake electrical stuff is being knocked out everywhere, indistinguishable from the real thing. Most punters don't care as the pay little and never think to question the quality.
Oh, and I see Claire is contacting Senh'r, but I expect they will say the same as Audio Technica said to me: if it isn't a "shop" we can't comment other than to say they are not authorised sellers. And, when they realised someone was punting out fake AT cans on ebay, they said there was NOTHING they could realistically do, and that they had to take it on the chin. even after posting a warning on ebay they were fake, the seller still had floods of A+ feedback with happy buyers!! Cost me a negative feedback in return!
Pay the extra, and buy safely.
That said, they may be real (legal slander get out!)This is more a general warning that a rant at the particular seller. The lack of a brand in the title is odd... although the seller is clearly passing them off as branded by the pic's logo and the cx300 tag.