I bought these PX-100 recently and they are the real deal. Paid 29.00+ and they sound wonderful, period. I have bought from Amazon many times so I think you can trust their normal listings. Buying from the "used and new" may be different story but I have had good luck with that as well.
Thanks a million for your kind guidance about this headphone being sold by merchants other than Amazon. Now, I shall place my order with one of them, and thanks to you I shall rest assured that they are genuine Sennheiser, and not imitations. Thanks for giving up your precious time to enlighten us customers of Amazon. Much appreciated. May God Almighty bless you,