It all depends on how long you've been with DTV, what price did you get for the HD-DVR (free?), when did they give you (purchase) the HD-DVR? If you haven't received or asked for anything over the last two years, I'd bet DTV would give you a free HD receiver with the caveat of a new 2-yr DTV commitment. This looks like a good case for CSR roulette.
i.e. Just keep calling different DTV CSR's until you get the price you're looking for.