My Comcast bill was creeping up, and up. I called and asked if there was a lower rate, even a lower speed would be okay. They quoted me a service that was 6Mbps for $34/month. I took it. It has been a year now, and they have not lowered my speed. Actually, my speed increased a month later from 20Mbps to 30Mbps, and I am still getting 30Mbps+- a year later all for the (hidden from sales material) entry class service rate.
My wife and I each have GV accounts. We use a daily plan with verizon with our cell. When we get a call to our GV number, the cell phone rings, but we don't answer the cell phone, we only answer it and talk with GV (FYI, Google Voice rings all phones associated with the account simultaneously). We do not get charged the daily rate with Verizon because we never answered the call with the cell phone (basic flip phone with "text" disabled).
The GV Quality with a headset is, frankly, quite excellent. It is far clearer than land-line in my experience (YMMV). So, we don't pay for high quality phone calls at all.
We use the cell phone as a 'mobile phone', perhaps, 50 times a year, so our cell phone costs about $100/year, GV is free, and our 30Mbps Internet is $34/month.