Apple seems to be going for threes. Three iPads, three MacBooks, three iPhones. Makes sense as a strategy, since it covers all budgets and size preferences.
There's actually a price point strategy where you have an overpriced low-end option and a high-priced bells-and-whistles option that are both designed to drive people to the middle option.
Case in point: the iPod Touch's three price points are $229, $299, and $399. $299 looks a lot more attractive when it's only $70 more than the option below it, but not many people would spend an extra $179 to get the 64GB version.
More on topic: I call BS on this. Calling the 6 the only headline worthy high-end phone that will be coming out this year is an outlandish claim to make at this point, and the price increase doesn't line up with anything else we've seen. It's possible they will release an iPhone Air or iPhone Pro, but the 6 will stay at the same price points.