said by djcrazy:
You can get up to 2 DTA's free of monthly fees for additional sets however, if you want all the channels like your main outlet (including any premium channels you subscribe to and the HD channels) along with the on demand access you will have to rent more boxes. I do not think there is any other service fee however.
You may have to pay $6-$8 outlet fee for tv2 and $8 HD fee (may be part of the deal with the HSI) Get 2 HD boxes same price as SD + hd box.
HD DVR is $16 (promo price lower)