You don't have to buy a composter; you can make it yourself:
https://www.google.com/search?q=home+composter+diy&ie=utf-8&oe=utf-8&aq=...

The idea is quite simple and its more about the ability to make sure there's enough moisture and air for the bacteria to break down the waste. You can dig a hole and use some of the building materials that's just laying around.

Good luck.