Don't count on it. As you probably know, 522s are currently reserved for new DHA leasing subscibers. The ones you see on ebay are mostly stolen, in some cases being sold by leasers who don't realize that they don't own what they're trying to sell. And, no doubt, some previous suckers are trying to resell units that they couldn't get activated.
Why not go for the DVR upgrade promo for existing customers? You can get a PVR721 for $249 and no "VOD" fees.
I used someone's suggestion about emailing firstname.lastname@example.org and get a reply in a few hours. Great Customer service and got the upgrade for $249 with no shipping and free installation. I am looking forward to the pip option in the 721.