Reddit mentions of Colloquial Italian: The Complete Course for Beginners (Colloquial Series)

Simply put, no. It's far too overpriced and, like others said, little more than fancy-looking flashcards. And you can get better flashcards that actually work to fit your memory by using a Spaced Repetition System like Anki (which is available for free and lets you download shared flashcard decks for free). As for the whole learning as a baby thing, that's not true. They don't expose you to pure listening in the language for a whole year and a half before you attempt to say something.

My recommendation, as a person who studies thirteen different languages: if you want to learn a second language, get a good course book with audio. I've yet to study Italian, although it's on my to-do list for later this year and I can already read a good amount of it since I'm a student or speaker of four other Romance languages. Here are three good courses:

• Teach Yourself Italian, from the very good Teach Yourself series,
  
• Colloquial Italian, published by Routledge, a highly respected publisher, especially when it comes to linguistic materials, and
  
• FSI Italian FAST (Familiarization And Short-term Training), available for free since it's in the public domain. Expect great efficiency from this course, especially since it was developed for people such as diplomats and the like.
  
  I wish you good luck, and remember: learning a new language should not be expensive. Anything that seems like too good of a deal in terms of results (like Rosetta Stone teaching you "naturally" or a product that promises fluency) should always be something to be regarded skeptically. It isn't impossible to teach yourself a lot of a language in a short period of time, like three months, but it'll require lots of dedication.
  
  Another idea: you might be able to sell your copy of Rosetta STone online, like on Craigslist, for some good revenue to buy a decent Italian course :)