Can someone explain to me if there are any benefits in purchasing a HD DVR? I'm jumping ship from DTV to Dish because the Dish has more stations to offer over DTV. I understand I will be paying $15 per mo. for the HD programing + DVR from Dish. Will that payment go away if I purchase a Dish Network HD DVR from someplace like ebay? If not, what are the advantages in owning my own HD DVR?