Yes, I bought them new from Amazon through a third party 4OurEars. I believe that they specialize in Grado products on their website so I have no reason to believe that they're not real. The box was also sealed. The number for these are #4xxx. In the picture, I have replaced the original L-cush with the G-cush which I find much more comfortable. I was a little shocked that the jack was not 1/4" as that's the only type that I've seen in online pictures, but I'd rather have a 1/8" jack anyway.
Interesting that these also have the red-backed drivers. There was an RS1i that someone posted recently over in the Grado thread with red drivers.
My PS500 (SN#37xx) have silver/black drivers
Edited by hsubox - 4/19/14 at 2:46pm