I was doing some shopping since my son thought he wanted the NFL Sunday Ticket, so my figures are pretty current. I didn't make the change because D* made 3 offers, 2 better than the national offers, and those 2 they wouldn't honor after they made them.
At 2 receivers with a 722k and a 612, Direct is more expensive per month in total any way I figure it. At 3 boxes, then D* becomes about the same and maybe cheaper depending on which box of E*'s you're comparing with. Frankly the 612 is the equivalent of the HRs from D*, so only about $4/month more per box.
Dish still has the best programming prices and the best DVRs out there, they just cost a little more...