It's been a long time since i look here, so to start JoomlaComment (I used so often !) is not suported any more and there is Compojoom comment now but u need to paid for using it ?
You don't pay for using it, you pay for the support and for the improvements we put in it.
Developing something like joomlacomment takes a lot of time and I had to find a way to monetize the project. Donations were not working, so I took the move to make it commercial - at the end of the day we all have to pay for rent and food.