You can use your own but then it has to run all the time and you need quite good hardware.
I can run at least 10 players the problem is just that i have blue LED's everywhere in my desktop and it is right next to my bed. Making a lot of noise too because it tends to heat up when i run with a lot of players. You can use Freon cooling but that is poisonous and expensive.
So just no... no one hosts servers for free...