Seattle. Upgraded from double play to triple play in order to get the X1 box. Cost of the "upgrade" was $308.50 ! Sent the thing back, not that impressed. Lots of bugs that they have had over a year to fix and have yet to do so. Tech told me I would just have to live with the problems. No way !
I'm in the Boston metro market. Comcast got me to sign up via a "win back" promotion, and I seem to have received X1 right off the bat. From what I can tell from my first bill, the DVR rental is $7 / month, and the service bundle (a triple play) looks standard as well. I don't see any additional X1 charge.
There has not been any anouncements that X1 platform will be any more than your existing service that continues to go up once or twice a year. Many posts say it's only for Triple Play subscribers for the early rollouts. There has not been any notices that the X1 DVR hardware will be anything additional in cost.