I am cheaper than many people I know, however...
When I first started with VOIP I was with a provider who charged a lot less a month than the local telco. I was a happy camper.
After a while I found a cheaper provider and switched to them.
Then I found GoogleVoice and used that with my PC. Later I got an Obi device and configured it for GV.
GoogleVoice is fine for those who absolutely want to have free calling. However, I found that companies such as
Voip.Ms and CallCentric, although they charge a dollar or so a month and a bit per minute, gave me more options and a lot less issues.
The forums here are full of questions about GoogleVoice and how to do this and how to do that. Porting a landline is not an easy thing. There are issues with 911, etc. You can't call some toll free numbers and sometimes there are other issues when Google changes something, etc. Google does not want you doing business through their service. Google does not have any real support except user forums, etc.
While free is enticing, I found that having accounts with CallCentric and
Voip.Ms have their pluses and few minuses. You pay a small fee and pay per call, but there are few hassles and problems.
I suggest people port their number to a paid provider and add a GV number if you want to play, but use the paid provider as your main service.