Incidentally, they said they'd give me a $10 credit if I send them the 811, which I own. I will probably take them up on that as the other methods of selling are too much trouble for the low rate of return...unlike a Dish 6k.
The Dish 811 makes an excellent non-HD DBS receiver, so if you have any other non-HD Dish receivers you should consider replacing them with the 811. My second receiver is a Dish 4700 that I bought back in the late 1990s and the 811 is so much faster and offers so many more connection options, I couldn't see sending the 811 to Dish for a few bucks and continuing to use the 4700.