Price breakdown: Dual tuner dvr (as mentioned before) is $17... Dual tuner receiver is $14... Single tuner box: $7, Single tuner dvr $10.
Put more simply, it's $7 per individual tuner (after the first receiver), and if that receiver has a dvr in it, that's an extra $3. So 2x 311's (or 211's etc) are $7 per month. A 612/512 (Single tuner with dvr) is $10 and dual tuner (Multi-tv) receivers are $7 per tv ($14) and if it's a dvr box (522/625/622/722/etc) it's $17. I do hope this clears up a few things. ....ok well it's simpler to me when I think about it that way anyway.
Also, there are certain specials available right now toward the "purchase" of SD dvr's right now. The only real way to find out if you qualify for them is to call an ask. Honestly, if you are buying receivers, i suggest getting single tuner boxes, they are much easier to install, requiring littlle to no special hardware other than good RG6 coax.
The 813 receiver is rumored to be available first quarter next year, and may be a better sollution for you, so it may be of benefit to wait.
Oh, and for anyone still paying a tv2 connection fee. Sign up for autopay, paperless billing, put an email adress on file, then call in and demand the fee be removed.