About 1 billion Android devices were sold in 2014, versus less than 200 million iPhones. Even if we assume your number is correct, that means 250 million Android devices were sold to users in high-income countries. Even if we assume that 50% of those users fall into the low-income range of their respective countries (the "Android users are on a budget"-argument), that's still 125 million Android devices owned by high-income users. The remaining 875 million users surely are gonna generate at least as much revenue as the remaining 75 million iPhone users in this scenario, don't you think?