Actually, I "stock" about a dozen remanufactured 2800s for that purpose, but it takes hours to get one to take the purple cards, as they were boxed with, and are "married to" the yellow cards. Some DISH CSRs know how to do it, but some don't and if something is done out of sequence, they become "toast".
Last night, I wasted over an hour trying to install one. We finaly got to the point where the receiver would acknowledge that the purple card was the valid on and let us see the promo channel (100, I think), but while it seemed to have selected the right guide, each time I stepped to a subscribed channel, it said we had no subscription. At this point, I'd just as soon pay a retail $100 for a 311 and be done with this.