Apple's iPhone 18 Pro models could be up to $200 more expensive, according to a prediction from analytics firm IDC. IDC expected Apple to raise iPhone 18 prices, but prior to yesterday's Mac and iPad price hike, the prediction was a $100 increase for the 18 Pro and Pro Max, and a $50 increase for the base models. IDC Senior Director of Data & Analytics Nabila Popal says the magnitude of the Mac and iPad price increase points to even higher iPhon…