Currently I own a 2 tuner Premiere with lifetime service and I received a Roamio upgrade offer from Tivo. I'm interested in a Roamio Plus and they are offering the DVR and lifetime service for $749.99 (a savings of $150.) After adding the item to the cart and entering the promo code, I see that the DVR is $350 and lifetime service is $399.99. Since I already have a unit activated with lifetime, this only looks like a $50 savings, not $150. From what I see, not a very good offer. Am I missing anything?