I have been using it for my game, and buying the source was
DEFINITELY
100%
WORTH IT.
I am curious what other people's impressions/experiences with it are.
I would recommend buying the source to anyone who is serious about making a game using cocos2d for iPhone, especially newbies like myself. I had never touched Obj-C before this (student with a few years of C++ experience, some Java) and in less than a month I have put together a nice little game that should be finished soon (programming wise it is 90% finished, still waiting on art/audio).
Let me put it this way: it took riq (someone who actually knows what he is doing) 2-3 months to put Sapus Tongue together. I don't even want to imagine how long it would take me or some other clueless person to do that same work on their own. I also don't know why anyone would spend 1-3 months figuring out how to do something they could pay a couple hundred bucks to have done instantly. If you are a professional and you could do all the basic stuff (physics, audio, scores, menus, buttons, etc.) yourself in a week or two, your time should be worth more than the amount the source costs.
Hopefully if you were on the fence about purchasing the code this will encourage you to bite the bullet/dive in headfirst with your project. My game is going to be way better/full featured than if I had tried to do it all myself, assuming that I eventually could have figured it all out on my own (which I doubt).
Daniel Piers
http://www.saltypiers.com