Hi,
I've been an iOS game developer for more than 6 years, 3 of which as a freelancer.
If I ever get hired for this project, I'll be using cocos2d as the game engine, with SimpleAudioEngine for the sound.
Could you give out further details about this project so I can make a better estimate on the cost?
What will the UI look like? Do you have the art assets readily available or at least an artist already hired? Or do you want to have it bundled along with the coding tasks?
Regards,
Julius