I have zero faith that a significant proportion of consumers will switch to iOS solely for privacy reasons. We've seen time and again that mainstream consumers would gladly surrender all their private info if it saves them $100.
Most people do care about privacy, but generally they are not even aware of how their privacy is being violated - Google and Facebook are very good at hiding the reality of these things.
But you're right, the cost is the ultimate factor for most people, especially in developing countries. I guess Apple doesn't care about complete market share, but if they did, they could just release an "iPhone Lite" for 150$ and good bye to Android market share. Imagine having 90%+ mobile phone market share - Apple could destroy the Google ad business.
