Hi
I use Skype for everything, it's essentially my phone.
PC to PC is free, if you want to use it to call phones it costs about $30 a year to call from your PC, or iPad.
I use the same account for both my PC my wife's PC and our iPad all for $30.
If you want to have a Skype Phone, (I don't have one) then you will get a Skype phone number etc, and it will cost a little more.
But I use my Skype account on my PC everyday.
I play online computer games on my PC and talk to my friends on Skype while we play, it's great.
Some times we talk for hours for free, and the quality keeps getting better.
Mike