You pay for the dedicated hosting.

These dedicated servers have a much higher bandwidth than regular broadband users get, and dedicated servers aren't turned off as often as home PCs. Also, since only Team Speak will be running (unlike a home PC where you will probably be using it to play Guild Wars at the same time) the sound quality will be much better and you will recieve messages faster.

Hosting a server from home may be free, but you pay for it in quality.