My bill is funky to figure out what your cost would be but Ill say this, AT&Ts bill was nuts. It was like $60.00 before I even made a call. jumped up to close to $70.00 by the time I moved to CDV.
If you are experiencing freq 2-5 sec drops while surfing I would be led to believe that is not the actual Comcast connection loosing synch every 2-5 secs. There might be something else going on.
Either way, Ive never had an issue with my phone, call clarity was actually greater with CDV. Calls were clearer and the actual volume of the caller increased when we switched.
Ive also made calls and have been online when I knew line guys were working on my run in particular to see what kind of impact preventative maintenance had on same time subscriber usage and can say I didnt notice anything issues.
CableTechs.org/"Horrible People with Integrity"