Depending on how much toon rendering you will be doing, you might want to explore the toon renderer included with Carrara. It may fill your needs, if not then you will be able to decide if you want the more powerful DCG Toon. The DCG toon plugin is better as indicated by the tests that Kixum posted, however, if your needs are like mine (sparse) you may get by with the included toon renderer. Yes as others have mentioned, Carrara plugins are inexpensive.